--- /dev/null
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/queue.h>
+#include <sys/param.h>
+#include <sys/uio.h>
+#include <sys/mman.h>
+#ifdef HAVE_SYS_FILE_H
+#include <sys/file.h>
+#endif
+
+#include <assert.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <time.h>
+#include <unistd.h>
+
+#include <openssl/sha.h>
+
+#include "mdb.h"
+
+#define DEBUG
+
+#ifdef DEBUG
+# define DPRINTF(...) do { fprintf(stderr, "%s:%d: ", __func__, __LINE__); \
+ fprintf(stderr, __VA_ARGS__); \
+ fprintf(stderr, "\n"); } while(0)
+#else
+# define DPRINTF(...)
+#endif
+
+#define PAGESIZE 4096
+#define MDB_MINKEYS 4
+#define MDB_MAGIC 0xBEEFC0DE
+#define MDB_VERSION 1
+#define MAXKEYSIZE 255
+
+#define P_INVALID 0xFFFFFFFF
+
+#define F_ISSET(w, f) (((w) & (f)) == (f))
+
+typedef ulong pgno_t;
+typedef uint16_t indx_t;
+
+/* Common header for all page types. Overflow pages
+ * occupy a number of contiguous pages with no
+ * headers on any page after the first.
+ */
+typedef struct MDB_page { /* represents a page of storage */
+ pgno_t mp_pgno; /* page number */
+#define P_BRANCH 0x01 /* branch page */
+#define P_LEAF 0x02 /* leaf page */
+#define P_OVERFLOW 0x04 /* overflow page */
+#define P_META 0x08 /* meta page */
+#define P_HEAD 0x10 /* header page */
+#define P_DIRTY 0x20 /* dirty page */
+ uint32_t mp_flags;
+#define mp_lower mp_pb.pb.pb_lower
+#define mp_upper mp_pb.pb.pb_upper
+#define mp_pages mp_pb.pb_pages
+ union page_bounds {
+ struct {
+ indx_t pb_lower; /* lower bound of free space */
+ indx_t pb_upper; /* upper bound of free space */
+ } pb;
+ uint32_t pb_pages; /* number of overflow pages */
+ } mp_pb;
+ indx_t mp_ptrs[1]; /* dynamic size */
+} MDB_page;
+
+#define PAGEHDRSZ offsetof(MDB_page, mp_ptrs)
+
+#define NUMKEYS(p) (((p)->mp_lower - PAGEHDRSZ) >> 1)
+#define SIZELEFT(p) (indx_t)((p)->mp_upper - (p)->mp_lower)
+#define PAGEFILL(env, p) (1000 * ((env)->me_head.mh_psize - PAGEHDRSZ - SIZELEFT(p)) / \
+ ((env)->me_head.mh_psize - PAGEHDRSZ))
+#define IS_LEAF(p) F_ISSET((p)->mp_flags, P_LEAF)
+#define IS_BRANCH(p) F_ISSET((p)->mp_flags, P_BRANCH)
+#define IS_OVERFLOW(p) F_ISSET((p)->mp_flags, P_OVERFLOW)
+
+typedef struct MDB_head { /* header page content */
+ uint32_t mh_magic;
+ uint32_t mh_version;
+ uint32_t mh_flags;
+ uint32_t mh_psize; /* page size */
+ void *mh_address; /* address for fixed mapping */
+ size_t mh_mapsize; /* size of mmap region */
+} MDB_head;
+
+typedef struct MDB_rootstat {
+ pgno_t mr_root; /* page number of root page */
+ MDB_stat mr_stat;
+} MDB_rootstat;
+
+typedef struct MDB_meta { /* meta (footer) page content */
+ pgno_t mm_root; /* page number of root page */
+ MDB_stat mm_stat;
+ pgno_t mm_prev_meta; /* previous meta page number */
+#define MDB_TOMBSTONE 0x01 /* file is replaced */
+ uint32_t mm_flags;
+#define mm_revisions mm_stat.ms_revisions
+#define mm_created_at mm_stat.ms_created_at
+ uint8_t mm_hash[SHA_DIGEST_LENGTH];
+} MDB_meta;
+
+typedef struct MDB_dhead { /* a dirty page */
+ SIMPLEQ_ENTRY(MDB_dpage) md_next; /* queue of dirty pages */
+ MDB_page *md_parent;
+ int md_pi; /* parent index */
+ int md_num;
+} MDB_dhead;
+
+typedef struct MDB_dpage {
+ MDB_dhead h;
+ MDB_page p;
+} MDB_dpage;
+
+SIMPLEQ_HEAD(dirty_queue, MDB_dpage);
+
+typedef struct MDB_pageparent {
+ MDB_page *mp_page;
+ MDB_page *mp_parent;
+ int mp_pi;
+} MDB_pageparent;
+
+static MDB_dpage *mdb_newpage(MDB_txn *txn, MDB_page *parent, int parent_idx, int num);
+static int mdb_touch(MDB_txn *txn, MDB_pageparent *mp);
+
+typedef struct MDB_ppage { /* ordered list of pages */
+ SLIST_ENTRY(MDB_ppage) mp_entry;
+ MDB_page *mp_page;
+ unsigned int mp_ki; /* cursor index on page */
+} MDB_ppage;
+SLIST_HEAD(page_stack, MDB_ppage);
+
+#define CURSOR_EMPTY(c) SLIST_EMPTY(&(c)->mc_stack)
+#define CURSOR_TOP(c) SLIST_FIRST(&(c)->mc_stack)
+#define CURSOR_POP(c) SLIST_REMOVE_HEAD(&(c)->mc_stack, mp_entry)
+#define CURSOR_PUSH(c,p) SLIST_INSERT_HEAD(&(c)->mc_stack, p, mp_entry)
+
+struct MDB_cursor {
+ MDB_db *mc_db;
+ MDB_txn *mc_txn;
+ struct page_stack mc_stack; /* stack of parent pages */
+ short mc_initialized; /* 1 if initialized */
+ short mc_eof; /* 1 if end is reached */
+};
+
+#define METAHASHLEN offsetof(MDB_meta, mm_hash)
+#define METADATA(p) ((void *)((char *)p + PAGEHDRSZ))
+
+typedef struct MDB_node {
+#define mn_pgno mn_p.np_pgno
+#define mn_dsize mn_p.np_dsize
+ union {
+ pgno_t np_pgno; /* child page number */
+ uint32_t np_dsize; /* leaf data size */
+ } mn_p;
+ uint16_t mn_ksize; /* key size */
+#define F_BIGDATA 0x01 /* data put on overflow page */
+ uint8_t mn_flags;
+ char mn_data[1];
+} MDB_node;
+
+struct MDB_txn {
+ pgno_t mt_root; /* current / new root page */
+ pgno_t mt_next_pgno; /* next unallocated page */
+ pgno_t mt_first_pgno;
+ MDB_env *mt_env;
+ struct dirty_queue *mt_dirty_queue; /* modified pages */
+#define MDB_TXN_RDONLY 0x01 /* read-only transaction */
+#define MDB_TXN_ERROR 0x02 /* an error has occurred */
+ unsigned int mt_flags;
+};
+
+/* Must be same as MDB_db, minus md_root/md_stat */
+typedef struct MDB_db0 {
+ unsigned int md_flags;
+ MDB_cmp_func *md_cmp; /* user compare function */
+ MDB_rel_func *md_rel; /* user relocate function */
+ MDB_db *md_parent; /* parent tree */
+ MDB_env *md_env;
+} MDB_db0;
+
+struct MDB_db {
+ unsigned int md_flags;
+ MDB_cmp_func *md_cmp; /* user compare function */
+ MDB_rel_func *md_rel; /* user relocate function */
+ MDB_db *md_parent; /* parent tree */
+ MDB_env *md_env;
+ pgno_t md_root; /* page number of root page */
+ MDB_stat md_stat;
+};
+
+struct MDB_env {
+ int me_fd;
+#define MDB_FIXPADDING 0x01 /* internal */
+ uint32_t me_flags;
+ char *me_path;
+ char *me_map;
+ MDB_head me_head;
+ MDB_db0 me_db; /* first DB, overlaps with meta */
+ MDB_meta me_meta;
+ MDB_txn *me_txn; /* current write transaction */
+ size_t me_mapsize;
+ off_t me_size; /* current file size */
+};
+
+#define NODESIZE offsetof(MDB_node, mn_data)
+
+#define INDXSIZE(k) (NODESIZE + ((k) == NULL ? 0 : (k)->mv_size))
+#define LEAFSIZE(k, d) (NODESIZE + (k)->mv_size + (d)->mv_size)
+#define NODEPTR(p, i) ((MDB_node *)((char *)(p) + (p)->mp_ptrs[i]))
+#define NODEKEY(node) (void *)((node)->mn_data)
+#define NODEDATA(node) (void *)((char *)(node)->mn_data + (node)->mn_ksize)
+#define NODEPGNO(node) ((node)->mn_pgno)
+#define NODEDSZ(node) ((node)->mn_dsize)
+
+#define MDB_COMMIT_PAGES 64 /* max number of pages to write in one commit */
+#define MDB_MAXCACHE_DEF 1024 /* max number of pages to keep in cache */
+
+static int mdb_search_page_root(MDB_db *db,
+ MDB_val *key,
+ MDB_cursor *cursor, int modify,
+ MDB_pageparent *mpp);
+static int mdb_search_page(MDB_db *db,
+ MDB_txn *txn, MDB_val *key,
+ MDB_cursor *cursor, int modify,
+ MDB_pageparent *mpp);
+
+static int mdbenv_write_header(MDB_env *env);
+static int mdbenv_read_header(MDB_env *env);
+static int mdb_check_meta_page(MDB_page *p);
+static int mdbenv_read_meta(MDB_env *env, pgno_t *p_next);
+static int mdbenv_write_meta(MDB_env *env, pgno_t root,
+ unsigned int flags);
+static MDB_page *mdbenv_get_page(MDB_env *env, pgno_t pgno);
+
+static MDB_node *mdb_search_node(MDB_db *db, MDB_page *mp,
+ MDB_val *key, int *exactp, unsigned int *kip);
+static int mdb_add_node(MDB_db *bt, MDB_page *mp,
+ indx_t indx, MDB_val *key, MDB_val *data,
+ pgno_t pgno, uint8_t flags);
+static void mdb_del_node(MDB_db *bt, MDB_page *mp,
+ indx_t indx);
+static int mdb_read_data(MDB_db *bt, MDB_page *mp,
+ MDB_node *leaf, MDB_val *data);
+
+static int mdb_rebalance(MDB_db *bt, MDB_pageparent *mp);
+static int mdb_update_key(MDB_db *bt, MDB_page *mp,
+ indx_t indx, MDB_val *key);
+static int mdb_move_node(MDB_db *bt,
+ MDB_pageparent *src, indx_t srcindx,
+ MDB_pageparent *dst, indx_t dstindx);
+static int mdb_merge(MDB_db *bt, MDB_pageparent *src,
+ MDB_pageparent *dst);
+static int mdb_split(MDB_db *bt, MDB_page **mpp,
+ unsigned int *newindxp, MDB_val *newkey,
+ MDB_val *newdata, pgno_t newpgno);
+static MDB_dpage *mdbenv_new_page(MDB_env *env, uint32_t flags, int num);
+
+static void cursor_pop_page(MDB_cursor *cursor);
+static MDB_ppage *cursor_push_page(MDB_cursor *cursor,
+ MDB_page *mp);
+
+static int mdb_set_key(MDB_db *bt, MDB_page *mp,
+ MDB_node *node, MDB_val *key);
+static int mdb_sibling(MDB_cursor *cursor, int move_right);
+static int mdb_cursor_next(MDB_cursor *cursor,
+ MDB_val *key, MDB_val *data);
+static int mdb_cursor_set(MDB_cursor *cursor,
+ MDB_val *key, MDB_val *data, int *exactp);
+static int mdb_cursor_first(MDB_cursor *cursor,
+ MDB_val *key, MDB_val *data);
+
+static size_t mdb_leaf_size(MDB_db *bt, MDB_val *key,
+ MDB_val *data);
+static size_t mdb_branch_size(MDB_db *bt, MDB_val *key);
+
+static pgno_t mdbenv_compact_tree(MDB_env *env, pgno_t pgno,
+ MDB_env *envc);
+
+static int memncmp(const void *s1, size_t n1,
+ const void *s2, size_t n2);
+static int memnrcmp(const void *s1, size_t n1,
+ const void *s2, size_t n2);
+
+static int
+memncmp(const void *s1, size_t n1, const void *s2, size_t n2)
+{
+ if (n1 < n2) {
+ if (memcmp(s1, s2, n1) == 0)
+ return -1;
+ }
+ else if (n1 > n2) {
+ if (memcmp(s1, s2, n2) == 0)
+ return 1;
+ }
+ return memcmp(s1, s2, n1);
+}
+
+static int
+memnrcmp(const void *s1, size_t n1, const void *s2, size_t n2)
+{
+ const unsigned char *p1;
+ const unsigned char *p2;
+
+ if (n1 == 0)
+ return n2 == 0 ? 0 : -1;
+
+ if (n2 == 0)
+ return n1 == 0 ? 0 : 1;
+
+ p1 = (const unsigned char *)s1 + n1 - 1;
+ p2 = (const unsigned char *)s2 + n2 - 1;
+
+ while (*p1 == *p2) {
+ if (p1 == s1)
+ return (p2 == s2) ? 0 : -1;
+ if (p2 == s2)
+ return (p1 == p2) ? 0 : 1;
+ p1--;
+ p2--;
+ }
+ return *p1 - *p2;
+}
+
+int
+mdb_cmp(MDB_db *db, const MDB_val *a, const MDB_val *b)
+{
+ return db->md_cmp(a, b);
+}
+
+static int
+_mdb_cmp(MDB_db *db, const MDB_val *key1, const MDB_val *key2)
+{
+ if (F_ISSET(db->md_flags, MDB_REVERSEKEY))
+ return memnrcmp(key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
+ else
+ return memncmp((char *)key1->mv_data, key1->mv_size, key2->mv_data, key2->mv_size);
+}
+
+/* Allocate new page(s) for writing */
+static MDB_dpage *
+mdb_newpage(MDB_txn *txn, MDB_page *parent, int parent_idx, int num)
+{
+ MDB_dpage *dp;
+
+ if ((dp = malloc(txn->mt_env->me_head.mh_psize * num + sizeof(MDB_dhead))) == NULL)
+ return NULL;
+ dp->h.md_num = num;
+ dp->h.md_parent = parent;
+ dp->h.md_pi = parent_idx;
+ SIMPLEQ_INSERT_TAIL(txn->mt_dirty_queue, dp, h.md_next);
+ dp->p.mp_pgno = txn->mt_next_pgno;
+ txn->mt_next_pgno += num;
+
+ return dp;
+}
+
+/* Touch a page: make it dirty and re-insert into tree with updated pgno.
+ */
+static int
+mdb_touch(MDB_txn *txn, MDB_pageparent *pp)
+{
+ int rc;
+ MDB_page *mp = pp->mp_page;
+ pgno_t pgno;
+ assert(txn != NULL);
+ assert(pp != NULL);
+
+ if (!F_ISSET(mp->mp_flags, P_DIRTY)) {
+ MDB_dpage *dp;
+ DPRINTF("touching page %lu -> %lu", mp->mp_pgno, txn->mt_next_pgno);
+ if ((dp = mdb_newpage(txn, pp->mp_parent, pp->mp_pi, 1)) == NULL)
+ return ENOMEM;
+ pgno = dp->p.mp_pgno;
+ bcopy(mp, &dp->p, txn->mt_env->me_head.mh_psize);
+ mp = &dp->p;
+ mp->mp_pgno = pgno;
+ mp->mp_flags |= P_DIRTY;
+
+ /* Update the page number to new touched page. */
+ if (pp->mp_parent != NULL)
+ NODEPGNO(NODEPTR(pp->mp_parent, pp->mp_pi)) = mp->mp_pgno;
+ pp->mp_page = mp;
+ }
+ return 0;
+}
+
+int
+mdbenv_sync(MDB_env *env)
+{
+ int rc = 0;
+ if (!F_ISSET(env->me_flags, MDB_NOSYNC)) {
+ if (fsync(env->me_fd))
+ rc = errno;
+ }
+ return rc;
+}
+
+int
+mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
+{
+ MDB_txn *txn;
+ int rc;
+
+ if (!rdonly && env->me_txn != NULL) {
+ DPRINTF("write transaction already begun");
+ return EBUSY;
+ }
+
+ if ((txn = calloc(1, sizeof(*txn))) == NULL) {
+ DPRINTF("calloc: %s", strerror(errno));
+ return ENOMEM;
+ }
+
+ if (rdonly) {
+ txn->mt_flags |= MDB_TXN_RDONLY;
+ } else {
+ txn->mt_dirty_queue = calloc(1, sizeof(*txn->mt_dirty_queue));
+ if (txn->mt_dirty_queue == NULL) {
+ free(txn);
+ return ENOMEM;
+ }
+ SIMPLEQ_INIT(txn->mt_dirty_queue);
+
+#if 0
+ DPRINTF("taking write lock on txn %p", txn);
+ if (flock(bt->fd, LOCK_EX | LOCK_NB) != 0) {
+ DPRINTF("flock: %s", strerror(errno));
+ errno = EBUSY;
+ free(txn->dirty_queue);
+ free(txn);
+ return NULL;
+ }
+#endif
+ env->me_txn = txn;
+ }
+
+ txn->mt_env = env;
+
+ if ((rc = mdbenv_read_meta(env, &txn->mt_next_pgno)) != MDB_SUCCESS) {
+ mdb_txn_abort(txn);
+ return rc;
+ }
+
+ txn->mt_first_pgno = txn->mt_next_pgno;
+ txn->mt_root = env->me_meta.mm_root;
+ DPRINTF("begin transaction on mdbenv %p, root page %lu", env, txn->mt_root);
+
+ *ret = txn;
+ return MDB_SUCCESS;
+}
+
+void
+mdb_txn_abort(MDB_txn *txn)
+{
+ MDB_dpage *dp;
+ MDB_env *env;
+
+ if (txn == NULL)
+ return;
+
+ env = txn->mt_env;
+ DPRINTF("abort transaction on mdbenv %p, root page %lu", env, txn->mt_root);
+
+ if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
+ /* Discard all dirty pages.
+ */
+ while (!SIMPLEQ_EMPTY(txn->mt_dirty_queue)) {
+ dp = SIMPLEQ_FIRST(txn->mt_dirty_queue);
+ SIMPLEQ_REMOVE_HEAD(txn->mt_dirty_queue, h.md_next);
+ free(dp);
+ }
+
+#if 0
+ DPRINTF("releasing write lock on txn %p", txn);
+ txn->bt->txn = NULL;
+ if (flock(txn->bt->fd, LOCK_UN) != 0) {
+ DPRINTF("failed to unlock fd %d: %s",
+ txn->bt->fd, strerror(errno));
+ }
+#endif
+ free(txn->mt_dirty_queue);
+ }
+
+ if (txn == env->me_txn)
+ env->me_txn = NULL;
+ free(txn);
+}
+
+int
+mdb_txn_commit(MDB_txn *txn)
+{
+ int n, done;
+ ssize_t rc;
+ off_t size;
+ MDB_dpage *dp;
+ MDB_env *env;
+ struct iovec iov[MDB_COMMIT_PAGES];
+
+ assert(txn != NULL);
+ assert(txn->mt_env != NULL);
+
+ env = txn->mt_env;
+
+ if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
+ DPRINTF("attempt to commit read-only transaction");
+ mdb_txn_abort(txn);
+ return EPERM;
+ }
+
+ if (txn != env->me_txn) {
+ DPRINTF("attempt to commit unknown transaction");
+ mdb_txn_abort(txn);
+ return EINVAL;
+ }
+
+ if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
+ DPRINTF("error flag is set, can't commit");
+ mdb_txn_abort(txn);
+ return EINVAL;
+ }
+
+ if (SIMPLEQ_EMPTY(txn->mt_dirty_queue))
+ goto done;
+
+ if (F_ISSET(env->me_flags, MDB_FIXPADDING)) {
+ size = lseek(env->me_fd, 0, SEEK_END);
+ size += env->me_head.mh_psize - (size % env->me_head.mh_psize);
+ DPRINTF("extending to multiple of page size: %lu", size);
+ if (ftruncate(env->me_fd, size) != 0) {
+ n = errno;
+ DPRINTF("ftruncate: %s", strerror(errno));
+ mdb_txn_abort(txn);
+ return n;
+ }
+ env->me_flags ^= MDB_FIXPADDING;
+ }
+
+ DPRINTF("committing transaction on mdbenv %p, root page %lu",
+ env, txn->mt_root);
+
+ /* Commit up to MDB_COMMIT_PAGES dirty pages to disk until done.
+ */
+ do {
+ n = 0;
+ done = 1;
+ SIMPLEQ_FOREACH(dp, txn->mt_dirty_queue, h.md_next) {
+ DPRINTF("committing page %lu", dp->p.mp_pgno);
+ iov[n].iov_len = env->me_head.mh_psize * dp->h.md_num;
+ iov[n].iov_base = &dp->p;
+ /* clear dirty flag */
+ dp->p.mp_flags &= ~P_DIRTY;
+ if (++n >= MDB_COMMIT_PAGES) {
+ done = 0;
+ break;
+ }
+ }
+
+ if (n == 0)
+ break;
+
+ DPRINTF("committing %u dirty pages", n);
+ rc = writev(env->me_fd, iov, n);
+ if (rc != (ssize_t)env->me_head.mh_psize*n) {
+ n = errno;
+ if (rc > 0)
+ DPRINTF("short write, filesystem full?");
+ else
+ DPRINTF("writev: %s", strerror(errno));
+ mdb_txn_abort(txn);
+ return n;
+ }
+
+ /* Drop the dirty pages.
+ */
+ while (!SIMPLEQ_EMPTY(txn->mt_dirty_queue)) {
+ dp = SIMPLEQ_FIRST(txn->mt_dirty_queue);
+ SIMPLEQ_REMOVE_HEAD(txn->mt_dirty_queue, h.md_next);
+ free(dp);
+ if (--n == 0)
+ break;
+ }
+ } while (!done);
+
+ if ((n = mdbenv_sync(env)) != 0 ||
+ (n = mdbenv_write_meta(env, txn->mt_root, 0)) != MDB_SUCCESS ||
+ (n = mdbenv_sync(env)) != 0) {
+ mdb_txn_abort(txn);
+ return n;
+ }
+ txn = NULL;
+ env->me_txn = NULL;
+
+done:
+ mdb_txn_abort(txn);
+
+ return MDB_SUCCESS;
+}
+
+static int
+mdbenv_write_header(MDB_env *env)
+{
+ struct stat sb;
+ MDB_head *h;
+ MDB_page *p;
+ ssize_t rc;
+ unsigned int psize;
+
+ DPRINTF("writing header page");
+ assert(env != NULL);
+
+ psize = sysconf(_SC_PAGE_SIZE);
+
+ if ((p = calloc(1, psize)) == NULL)
+ return ENOMEM;
+ p->mp_flags = P_HEAD;
+
+ env->me_head.mh_psize = psize;
+ env->me_head.mh_flags = env->me_flags & 0xffff;
+
+ h = METADATA(p);
+ bcopy(&env->me_head, h, sizeof(*h));
+
+ rc = write(env->me_fd, p, env->me_head.mh_psize);
+ free(p);
+ if (rc != (ssize_t)env->me_head.mh_psize) {
+ int err = errno;
+ if (rc > 0)
+ DPRINTF("short write, filesystem full?");
+ return err;
+ }
+
+ return MDB_SUCCESS;
+}
+
+static int
+mdbenv_read_header(MDB_env *env)
+{
+ char page[PAGESIZE];
+ MDB_page *p;
+ MDB_head *h;
+ int rc;
+
+ assert(env != NULL);
+
+ /* We don't know the page size yet, so use a minimum value.
+ */
+
+ if ((rc = pread(env->me_fd, page, PAGESIZE, 0)) == 0) {
+ return ENOENT;
+ } else if (rc != PAGESIZE) {
+ if (rc > 0)
+ errno = EINVAL;
+ DPRINTF("read: %s", strerror(errno));
+ return errno;
+ }
+
+ p = (MDB_page *)page;
+
+ if (!F_ISSET(p->mp_flags, P_HEAD)) {
+ DPRINTF("page %lu not a header page", p->mp_pgno);
+ return EINVAL;
+ }
+
+ h = METADATA(p);
+ if (h->mh_magic != MDB_MAGIC) {
+ DPRINTF("header has invalid magic");
+ return EINVAL;
+ }
+
+ if (h->mh_version != MDB_VERSION) {
+ DPRINTF("database is version %u, expected version %u",
+ h->mh_version, MDB_VERSION);
+ return EINVAL;
+ }
+
+ bcopy(h, &env->me_head, sizeof(*h));
+ return 0;
+}
+
+static int
+mdbenv_write_meta(MDB_env *env, pgno_t root, unsigned int flags)
+{
+ MDB_dpage *dp;
+ MDB_meta *meta;
+ ssize_t rc;
+
+ DPRINTF("writing meta page for root page %lu", root);
+
+ assert(env != NULL);
+ assert(env->me_txn != NULL);
+
+ if ((dp = mdbenv_new_page(env, P_META, 1)) == NULL)
+ return ENOMEM;
+
+ env->me_meta.mm_prev_meta = env->me_meta.mm_root;
+ env->me_meta.mm_root = root;
+ env->me_meta.mm_flags = flags;
+ env->me_meta.mm_created_at = time(0);
+ env->me_meta.mm_revisions++;
+ SHA1((unsigned char *)&env->me_meta, METAHASHLEN, env->me_meta.mm_hash);
+
+ /* Copy the meta data changes to the new meta page. */
+ meta = METADATA(&dp->p);
+ bcopy(&env->me_meta, meta, sizeof(*meta));
+
+ rc = write(env->me_fd, &dp->p, env->me_head.mh_psize);
+ SIMPLEQ_REMOVE_HEAD(env->me_txn->mt_dirty_queue, h.md_next);
+ free(dp);
+ if (rc != (ssize_t)env->me_head.mh_psize) {
+ int err = errno;
+ if (rc > 0)
+ DPRINTF("short write, filesystem full?");
+ return err;
+ }
+
+ if ((env->me_size = lseek(env->me_fd, 0, SEEK_END)) == -1) {
+ DPRINTF("failed to update file size: %s", strerror(errno));
+ env->me_size = 0;
+ }
+
+ return MDB_SUCCESS;
+}
+
+/* Returns true if page p is a valid meta page, false otherwise.
+ */
+static int
+mdb_check_meta_page(MDB_page *p)
+{
+ MDB_meta *m;
+ unsigned char hash[SHA_DIGEST_LENGTH];
+
+ m = METADATA(p);
+ if (!F_ISSET(p->mp_flags, P_META)) {
+ DPRINTF("page %lu not a meta page", p->mp_pgno);
+ return EINVAL;
+ }
+
+ if (m->mm_root >= p->mp_pgno && m->mm_root != P_INVALID) {
+ DPRINTF("page %lu points to an invalid root page", p->mp_pgno);
+ return EINVAL;
+ }
+
+ SHA1((unsigned char *)m, METAHASHLEN, hash);
+ if (bcmp(hash, m->mm_hash, SHA_DIGEST_LENGTH) != 0) {
+ DPRINTF("page %lu has an invalid digest", p->mp_pgno);
+ return EINVAL;
+ }
+
+ return 0;
+}
+
+static int
+mdbenv_read_meta(MDB_env *env, pgno_t *p_next)
+{
+ MDB_page *mp;
+ MDB_meta *meta;
+ pgno_t meta_pgno, next_pgno;
+ off_t size;
+
+ assert(env != NULL);
+
+ if ((size = lseek(env->me_fd, 0, SEEK_END)) == -1)
+ goto fail;
+
+ DPRINTF("mdbenv_read_meta: size = %lu", size);
+
+ if (size < env->me_size) {
+ DPRINTF("file has shrunk!");
+ errno = EIO;
+ goto fail;
+ }
+
+ if (size == env->me_head.mh_psize) { /* there is only the header */
+ if (p_next != NULL)
+ *p_next = 1;
+ return MDB_SUCCESS; /* new file */
+ }
+
+ next_pgno = size / env->me_head.mh_psize;
+ if (next_pgno == 0) {
+ DPRINTF("corrupt file");
+ errno = EIO;
+ goto fail;
+ }
+
+ meta_pgno = next_pgno - 1;
+
+ if (size % env->me_head.mh_psize != 0) {
+ DPRINTF("filesize not a multiple of the page size!");
+ env->me_flags |= MDB_FIXPADDING;
+ next_pgno++;
+ }
+
+ if (p_next != NULL)
+ *p_next = next_pgno;
+
+ if (size == env->me_size) {
+ DPRINTF("size unchanged, keeping current meta page");
+ if (F_ISSET(env->me_meta.mm_flags, MDB_TOMBSTONE)) {
+ DPRINTF("file is dead");
+ errno = ESTALE;
+ return MDB_FAIL;
+ } else
+ return MDB_SUCCESS;
+ } else {
+ env->me_size = size;
+ }
+
+ while (meta_pgno > 0) {
+ if ((mp = mdbenv_get_page(env, meta_pgno)) == NULL)
+ break;
+ if (!mdb_check_meta_page(mp)) {
+ meta = METADATA(mp);
+ DPRINTF("flags = 0x%x", meta->mm_flags);
+ if (F_ISSET(meta->mm_flags, MDB_TOMBSTONE)) {
+ DPRINTF("file is dead");
+ errno = ESTALE;
+ return MDB_FAIL;
+ } else {
+ /* Make copy of last meta page. */
+ bcopy(meta, &env->me_meta, sizeof(env->me_meta));
+ return MDB_SUCCESS;
+ }
+ }
+ --meta_pgno; /* scan backwards to first valid meta page */
+ }
+
+ errno = EIO;
+fail:
+ if (p_next != NULL)
+ *p_next = P_INVALID;
+ return MDB_FAIL;
+}
+
+int
+mdbenv_create(MDB_env **env, size_t size)
+{
+ MDB_env *e;
+
+ if (!size) return EINVAL;
+
+ e = calloc(1, sizeof(*e));
+ if (!e) return ENOMEM;
+
+ e->me_head.mh_magic = MDB_MAGIC;
+ e->me_head.mh_version = MDB_VERSION;
+ e->me_mapsize = e->me_head.mh_mapsize = size;
+ e->me_db.md_env = e;
+ *env = e;
+ return MDB_SUCCESS;
+}
+
+int
+mdbenv_open2(MDB_env *env, unsigned int flags)
+{
+ int i, newenv = 0;
+
+ i = fcntl(env->me_fd, F_GETFL, 0);
+ if (fcntl(env->me_fd, F_SETFL, i | O_APPEND) == -1)
+ return errno;
+
+ env->me_flags = flags;
+ env->me_flags &= ~MDB_FIXPADDING;
+ env->me_meta.mm_root = P_INVALID;
+
+ if ((i = mdbenv_read_header(env)) != 0) {
+ if (i != ENOENT)
+ return i;
+ DPRINTF("new mdbenv");
+ newenv = 1;
+ }
+
+ i = MAP_SHARED;
+ if (env->me_head.mh_address && (flags & MDB_FIXEDMAP))
+ i |= MAP_FIXED;
+ env->me_map = mmap(env->me_head.mh_address, env->me_mapsize, PROT_READ, i,
+ env->me_fd, 0);
+ if (env->me_map == MAP_FAILED)
+ return errno;
+
+ if (newenv) {
+ env->me_head.mh_mapsize = env->me_mapsize;
+ if (flags & MDB_FIXEDMAP)
+ env->me_head.mh_address = env->me_map;
+ i = mdbenv_write_header(env);
+ if (i != MDB_SUCCESS) {
+ munmap(env->me_map, env->me_mapsize);
+ return i;
+ }
+ }
+
+ if ((i = mdbenv_read_meta(env, NULL)) != 0)
+ return i;
+
+ DPRINTF("opened database version %u, pagesize %u",
+ env->me_head.mh_version, env->me_head.mh_psize);
+ DPRINTF("timestamp: %s", ctime(&env->me_meta.mm_created_at));
+ DPRINTF("depth: %u", env->me_meta.mm_stat.ms_depth);
+ DPRINTF("entries: %lu", env->me_meta.mm_stat.ms_entries);
+ DPRINTF("revisions: %lu", env->me_meta.mm_stat.ms_revisions);
+ DPRINTF("branch pages: %lu", env->me_meta.mm_stat.ms_branch_pages);
+ DPRINTF("leaf pages: %lu", env->me_meta.mm_stat.ms_leaf_pages);
+ DPRINTF("overflow pages: %lu", env->me_meta.mm_stat.ms_overflow_pages);
+ DPRINTF("root: %lu", env->me_meta.mm_root);
+ DPRINTF("previous me_meta.me_page: %lu", env->me_meta.mm_prev_meta);
+
+ return MDB_SUCCESS;
+}
+
+int
+mdbenv_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
+{
+ int oflags, rc;
+
+ if (F_ISSET(flags, MDB_RDONLY))
+ oflags = O_RDONLY;
+ else
+ oflags = O_RDWR | O_CREAT | O_APPEND;
+
+ if ((env->me_fd = open(path, oflags, mode)) == -1)
+ return errno;
+
+ if ((rc = mdbenv_open2(env, flags)) != MDB_SUCCESS) {
+ close(env->me_fd);
+ env->me_fd = -1;
+ } else {
+ env->me_path = strdup(path);
+ DPRINTF("opened dbenv %p", env);
+ }
+
+ return rc;
+}
+
+void
+mdbenv_close(MDB_env *env)
+{
+ if (env == NULL)
+ return;
+
+ free(env->me_path);
+
+ if (env->me_map) {
+ munmap(env->me_map, env->me_mapsize);
+ }
+ close(env->me_fd);
+}
+
+/* Search for key within a leaf page, using binary search.
+ * Returns the smallest entry larger or equal to the key.
+ * If exactp is non-null, stores whether the found entry was an exact match
+ * in *exactp (1 or 0).
+ * If kip is non-null, stores the index of the found entry in *kip.
+ * If no entry larger or equal to the key is found, returns NULL.
+ */
+static MDB_node *
+mdb_search_node(MDB_db *bt, MDB_page *mp, MDB_val *key,
+ int *exactp, unsigned int *kip)
+{
+ unsigned int i = 0;
+ int low, high;
+ int rc = 0;
+ MDB_node *node;
+ MDB_val nodekey;
+
+ DPRINTF("searching %lu keys in %s page %lu",
+ NUMKEYS(mp),
+ IS_LEAF(mp) ? "leaf" : "branch",
+ mp->mp_pgno);
+
+ assert(NUMKEYS(mp) > 0);
+
+ bzero(&nodekey, sizeof(nodekey));
+
+ low = IS_LEAF(mp) ? 0 : 1;
+ high = NUMKEYS(mp) - 1;
+ while (low <= high) {
+ i = (low + high) >> 1;
+ node = NODEPTR(mp, i);
+
+ nodekey.mv_size = node->mn_ksize;
+ nodekey.mv_data = NODEKEY(node);
+
+ if (bt->md_cmp)
+ rc = bt->md_cmp(key, &nodekey);
+ else
+ rc = _mdb_cmp(bt, key, &nodekey);
+
+ if (IS_LEAF(mp))
+ DPRINTF("found leaf index %u [%.*s], rc = %i",
+ i, (int)nodekey.mv_size, (char *)nodekey.mv_data, rc);
+ else
+ DPRINTF("found branch index %u [%.*s -> %lu], rc = %i",
+ i, (int)node->mn_ksize, (char *)NODEKEY(node),
+ node->mn_pgno, rc);
+
+ if (rc == 0)
+ break;
+ if (rc > 0)
+ low = i + 1;
+ else
+ high = i - 1;
+ }
+
+ if (rc > 0) { /* Found entry is less than the key. */
+ i++; /* Skip to get the smallest entry larger than key. */
+ if (i >= NUMKEYS(mp))
+ /* There is no entry larger or equal to the key. */
+ return NULL;
+ }
+ if (exactp)
+ *exactp = (rc == 0);
+ if (kip) /* Store the key index if requested. */
+ *kip = i;
+
+ return NODEPTR(mp, i);
+}
+
+static void
+cursor_pop_page(MDB_cursor *cursor)
+{
+ MDB_ppage *top;
+
+ top = CURSOR_TOP(cursor);
+ CURSOR_POP(cursor);
+
+ DPRINTF("popped page %lu off cursor %p", top->mp_page->mp_pgno, cursor);
+
+ free(top);
+}
+
+static MDB_ppage *
+cursor_push_page(MDB_cursor *cursor, MDB_page *mp)
+{
+ MDB_ppage *ppage;
+
+ DPRINTF("pushing page %lu on cursor %p", mp->mp_pgno, cursor);
+
+ if ((ppage = calloc(1, sizeof(*ppage))) == NULL)
+ return NULL;
+ ppage->mp_page = mp;
+ CURSOR_PUSH(cursor, ppage);
+ return ppage;
+}
+
+static MDB_page *
+mdbenv_get_page(MDB_env *env, pgno_t pgno)
+{
+ MDB_page *p = NULL;
+ MDB_txn *txn = env->me_txn;
+
+ if (txn && pgno >= txn->mt_first_pgno &&
+ !SIMPLEQ_EMPTY(txn->mt_dirty_queue)) {
+ MDB_dpage *dp;
+ SIMPLEQ_FOREACH(dp, txn->mt_dirty_queue, h.md_next) {
+ if (dp->p.mp_pgno == pgno) {
+ p = &dp->p;
+ break;
+ }
+ }
+ } else {
+ p = (MDB_page *)(env->me_map + env->me_head.mh_psize * pgno);
+ }
+ return p;
+}
+
+static int
+mdb_search_page_root(MDB_db *bt, MDB_val *key,
+ MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
+{
+ MDB_page *mp = mpp->mp_page;
+ int rc;
+
+ if (cursor && cursor_push_page(cursor, mp) == NULL)
+ return MDB_FAIL;
+
+ while (IS_BRANCH(mp)) {
+ unsigned int i = 0;
+ MDB_node *node;
+
+ DPRINTF("branch page %lu has %lu keys", mp->mp_pgno, NUMKEYS(mp));
+ assert(NUMKEYS(mp) > 1);
+ DPRINTF("found index 0 to page %lu", NODEPGNO(NODEPTR(mp, 0)));
+
+ if (key == NULL) /* Initialize cursor to first page. */
+ i = 0;
+ else {
+ int exact;
+ node = mdb_search_node(bt, mp, key, &exact, &i);
+ if (node == NULL)
+ i = NUMKEYS(mp) - 1;
+ else if (!exact) {
+ assert(i > 0);
+ i--;
+ }
+ }
+
+ if (key)
+ DPRINTF("following index %u for key %.*s",
+ i, (int)key->mv_size, (char *)key->mv_data);
+ assert(i >= 0 && i < NUMKEYS(mp));
+ node = NODEPTR(mp, i);
+
+ if (cursor)
+ CURSOR_TOP(cursor)->mp_ki = i;
+
+ mpp->mp_parent = mp;
+ if ((mp = mdbenv_get_page(bt->md_env, NODEPGNO(node))) == NULL)
+ return MDB_FAIL;
+ mpp->mp_pi = i;
+ mpp->mp_page = mp;
+
+ if (cursor && cursor_push_page(cursor, mp) == NULL)
+ return MDB_FAIL;
+
+ if (modify && (rc = mdb_touch(bt->md_env->me_txn, mpp)))
+ return rc;
+ mp = mpp->mp_page;
+ }
+
+ if (!IS_LEAF(mp)) {
+ DPRINTF("internal error, index points to a %02X page!?",
+ mp->mp_flags);
+ return MDB_FAIL;
+ }
+
+ DPRINTF("found leaf page %lu for key %.*s", mp->mp_pgno,
+ key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL);
+
+ return MDB_SUCCESS;
+}
+
+/* Search for the page a given key should be in.
+ * Stores a pointer to the found page in *mpp.
+ * If key is NULL, search for the lowest page (used by mdb_cursor_first).
+ * If cursor is non-null, pushes parent pages on the cursor stack.
+ * If modify is true, visited pages are updated with new page numbers.
+ */
+static int
+mdb_search_page(MDB_db *db, MDB_txn *txn, MDB_val *key,
+ MDB_cursor *cursor, int modify, MDB_pageparent *mpp)
+{
+ int rc;
+ pgno_t root;
+
+ /* Can't modify pages outside a transaction. */
+ if (txn == NULL && modify) {
+ return EINVAL;
+ }
+
+ /* Choose which root page to start with. If a transaction is given
+ * use the root page from the transaction, otherwise read the last
+ * committed root page.
+ */
+ if (txn == NULL) {
+ if ((rc = mdbenv_read_meta(db->md_env, NULL)) != MDB_SUCCESS)
+ return rc;
+ root = db->md_env->me_meta.mm_root;
+ } else if (F_ISSET(txn->mt_flags, MDB_TXN_ERROR)) {
+ DPRINTF("transaction has failed, must abort");
+ return EINVAL;
+ } else
+ root = txn->mt_root;
+
+ if (root == P_INVALID) { /* Tree is empty. */
+ DPRINTF("tree is empty");
+ return ENOENT;
+ }
+
+ if ((mpp->mp_page = mdbenv_get_page(db->md_env, root)) == NULL)
+ return MDB_FAIL;
+
+ DPRINTF("root page has flags 0x%X", mpp->mp_page->mp_flags);
+
+ if (modify && !F_ISSET(mpp->mp_page->mp_flags, P_DIRTY)) {
+ mpp->mp_parent = NULL;
+ mpp->mp_pi = 0;
+ if ((rc = mdb_touch(txn, mpp)))
+ return rc;
+ txn->mt_root = mpp->mp_page->mp_pgno;
+ }
+
+ return mdb_search_page_root(db, key, cursor, modify, mpp);
+}
+
+static int
+mdb_read_data(MDB_db *db, MDB_page *mp, MDB_node *leaf,
+ MDB_val *data)
+{
+ MDB_page *omp; /* overflow mpage */
+ size_t psz;
+ size_t max;
+ size_t sz = 0;
+ pgno_t pgno;
+
+ bzero(data, sizeof(*data));
+ max = db->md_env->me_head.mh_psize - PAGEHDRSZ;
+
+ if (!F_ISSET(leaf->mn_flags, F_BIGDATA)) {
+ data->mv_size = leaf->mn_dsize;
+ data->mv_data = NODEDATA(leaf);
+ return MDB_SUCCESS;
+ }
+
+ /* Read overflow data.
+ */
+ data->mv_size = leaf->mn_dsize;
+ bcopy(NODEDATA(leaf), &pgno, sizeof(pgno));
+ if ((omp = mdbenv_get_page(db->md_env, pgno)) == NULL) {
+ DPRINTF("read overflow page %lu failed", pgno);
+ return MDB_FAIL;
+ }
+ data->mv_data = omp;
+
+ return MDB_SUCCESS;
+}
+
+int
+mdb_get(MDB_db *db, MDB_txn *txn,
+ MDB_val *key, MDB_val *data)
+{
+ int rc, exact;
+ MDB_node *leaf;
+ MDB_pageparent mpp;
+
+ assert(key);
+ assert(data);
+ DPRINTF("===> get key [%.*s]", (int)key->mv_size, (char *)key->mv_data);
+
+ if (db == NULL)
+ return EINVAL;
+
+ if (txn != NULL && db->md_env != txn->mt_env) {
+ return EINVAL;
+ }
+
+ if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
+ return EINVAL;
+ }
+
+ if ((rc = mdb_search_page(db, txn, key, NULL, 0, &mpp)) != MDB_SUCCESS)
+ return rc;
+
+ leaf = mdb_search_node(db, mpp.mp_page, key, &exact, NULL);
+ if (leaf && exact)
+ rc = mdb_read_data(db, mpp.mp_page, leaf, data);
+ else {
+ rc = ENOENT;
+ }
+
+ return rc;
+}
+
+static int
+mdb_sibling(MDB_cursor *cursor, int move_right)
+{
+ int rc;
+ MDB_node *indx;
+ MDB_ppage *parent, *top;
+ MDB_page *mp;
+
+ top = CURSOR_TOP(cursor);
+ if ((parent = SLIST_NEXT(top, mp_entry)) == NULL) {
+ return ENOENT; /* root has no siblings */
+ }
+
+ DPRINTF("parent page is page %lu, index %u",
+ parent->mp_page->mp_pgno, parent->mp_ki);
+
+ cursor_pop_page(cursor);
+ if (move_right ? (parent->mp_ki + 1 >= NUMKEYS(parent->mp_page))
+ : (parent->mp_ki == 0)) {
+ DPRINTF("no more keys left, moving to %s sibling",
+ move_right ? "right" : "left");
+ if ((rc = mdb_sibling(cursor, move_right)) != MDB_SUCCESS)
+ return rc;
+ parent = CURSOR_TOP(cursor);
+ } else {
+ if (move_right)
+ parent->mp_ki++;
+ else
+ parent->mp_ki--;
+ DPRINTF("just moving to %s index key %u",
+ move_right ? "right" : "left", parent->mp_ki);
+ }
+ assert(IS_BRANCH(parent->mp_page));
+
+#if 0
+ indx = NODEPTR(parent->mp_page, parent->mp_ki);
+ if ((mp = mdbenv_get_page(cursor->bt, indx->n_pgno)) == NULL)
+ return MDB_FAIL;
+ mp->parent = parent->mp_page;
+ mp->parent_index = parent->mp_ki;
+#endif
+
+ cursor_push_page(cursor, mp);
+
+ return MDB_SUCCESS;
+}
+
+static int
+mdb_set_key(MDB_db *bt, MDB_page *mp, MDB_node *node,
+ MDB_val *key)
+{
+ if (key == NULL)
+ return 0;
+
+ key->mv_size = node->mn_ksize;
+ key->mv_data = NODEKEY(node);
+
+ return 0;
+}
+
+static int
+mdb_cursor_next(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
+{
+ MDB_ppage *top;
+ MDB_page *mp;
+ MDB_node *leaf;
+
+ if (cursor->mc_eof) {
+ return ENOENT;
+ }
+
+ assert(cursor->mc_initialized);
+
+ top = CURSOR_TOP(cursor);
+ mp = top->mp_page;
+
+ DPRINTF("cursor_next: top page is %lu in cursor %p", mp->mp_pgno, cursor);
+
+ if (top->mp_ki + 1 >= NUMKEYS(mp)) {
+ DPRINTF("=====> move to next sibling page");
+ if (mdb_sibling(cursor, 1) != MDB_SUCCESS) {
+ cursor->mc_eof = 1;
+ return ENOENT;
+ }
+ top = CURSOR_TOP(cursor);
+ mp = top->mp_page;
+ DPRINTF("next page is %lu, key index %u", mp->mp_pgno, top->mp_ki);
+ } else
+ top->mp_ki++;
+
+ DPRINTF("==> cursor points to page %lu with %lu keys, key index %u",
+ mp->mp_pgno, NUMKEYS(mp), top->mp_ki);
+
+ assert(IS_LEAF(mp));
+ leaf = NODEPTR(mp, top->mp_ki);
+
+ if (data && mdb_read_data(cursor->mc_db, mp, leaf, data) != MDB_SUCCESS)
+ return MDB_FAIL;
+
+ return mdb_set_key(cursor->mc_db, mp, leaf, key);
+}
+
+static int
+mdb_cursor_set(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
+ int *exactp)
+{
+ int rc;
+ MDB_node *leaf;
+ MDB_ppage *top;
+ MDB_pageparent mpp;
+
+ assert(cursor);
+ assert(key);
+ assert(key->mv_size > 0);
+
+ rc = mdb_search_page(cursor->mc_db, cursor->mc_txn, key, cursor, 0, &mpp);
+ if (rc != MDB_SUCCESS)
+ return rc;
+ assert(IS_LEAF(mpp.mp_page));
+
+ top = CURSOR_TOP(cursor);
+ leaf = mdb_search_node(cursor->mc_db, mpp.mp_page, key, exactp, &top->mp_ki);
+ if (exactp != NULL && !*exactp) {
+ /* MDB_CURSOR_EXACT specified and not an exact match. */
+ return ENOENT;
+ }
+
+ if (leaf == NULL) {
+ DPRINTF("===> inexact leaf not found, goto sibling");
+ if ((rc = mdb_sibling(cursor, 1)) != MDB_SUCCESS)
+ return rc; /* no entries matched */
+ top = CURSOR_TOP(cursor);
+ top->mp_ki = 0;
+ mpp.mp_page = top->mp_page;
+ assert(IS_LEAF(mpp.mp_page));
+ leaf = NODEPTR(mpp.mp_page, 0);
+ }
+
+ cursor->mc_initialized = 1;
+ cursor->mc_eof = 0;
+
+ if (data && (rc = mdb_read_data(cursor->mc_db, mpp.mp_page, leaf, data)) != MDB_SUCCESS)
+ return rc;
+
+ rc = mdb_set_key(cursor->mc_db, mpp.mp_page, leaf, key);
+ if (rc == MDB_SUCCESS) {
+ DPRINTF("==> cursor placed on key %.*s",
+ (int)key->mv_size, (char *)key->mv_data);
+ ;
+ }
+
+ return rc;
+}
+
+static int
+mdb_cursor_first(MDB_cursor *cursor, MDB_val *key, MDB_val *data)
+{
+ int rc;
+ MDB_pageparent mpp;
+ MDB_node *leaf;
+
+ rc = mdb_search_page(cursor->mc_db, cursor->mc_txn, NULL, cursor, 0, &mpp);
+ if (rc != MDB_SUCCESS)
+ return rc;
+ assert(IS_LEAF(mpp.mp_page));
+
+ leaf = NODEPTR(mpp.mp_page, 0);
+ cursor->mc_initialized = 1;
+ cursor->mc_eof = 0;
+
+ if (data && (rc = mdb_read_data(cursor->mc_db, mpp.mp_page, leaf, data)) != MDB_SUCCESS)
+ return rc;
+
+ return mdb_set_key(cursor->mc_db, mpp.mp_page, leaf, key);
+}
+
+int
+mdb_cursor_get(MDB_cursor *cursor, MDB_val *key, MDB_val *data,
+ MDB_cursor_op op)
+{
+ int rc;
+ int exact = 0;
+
+ assert(cursor);
+
+ switch (op) {
+ case MDB_CURSOR:
+ case MDB_CURSOR_EXACT:
+ while (CURSOR_TOP(cursor) != NULL)
+ cursor_pop_page(cursor);
+ if (key == NULL || key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
+ rc = EINVAL;
+ } else if (op == MDB_CURSOR_EXACT)
+ rc = mdb_cursor_set(cursor, key, data, &exact);
+ else
+ rc = mdb_cursor_set(cursor, key, data, NULL);
+ break;
+ case MDB_NEXT:
+ if (!cursor->mc_initialized)
+ rc = mdb_cursor_first(cursor, key, data);
+ else
+ rc = mdb_cursor_next(cursor, key, data);
+ break;
+ case MDB_FIRST:
+ while (CURSOR_TOP(cursor) != NULL)
+ cursor_pop_page(cursor);
+ rc = mdb_cursor_first(cursor, key, data);
+ break;
+ default:
+ DPRINTF("unhandled/unimplemented cursor operation %u", op);
+ rc = EINVAL;
+ break;
+ }
+
+ return rc;
+}
+
+/* Allocate a page and initialize it
+ */
+static MDB_dpage *
+mdbenv_new_page(MDB_env *env, uint32_t flags, int num)
+{
+ MDB_dpage *dp;
+
+ assert(env != NULL);
+ assert(env->me_txn != NULL);
+
+ DPRINTF("allocating new mpage %lu, page size %u",
+ env->me_txn->mt_next_pgno, env->me_head.mh_psize);
+ if ((dp = mdb_newpage(env->me_txn, NULL, 0, num)) == NULL)
+ return NULL;
+ dp->p.mp_flags = flags;
+ dp->p.mp_lower = PAGEHDRSZ;
+ dp->p.mp_upper = env->me_head.mh_psize;
+
+ if (IS_BRANCH(&dp->p))
+ env->me_meta.mm_stat.ms_branch_pages++;
+ else if (IS_LEAF(&dp->p))
+ env->me_meta.mm_stat.ms_leaf_pages++;
+ else if (IS_OVERFLOW(&dp->p)) {
+ env->me_meta.mm_stat.ms_overflow_pages += num;
+ dp->p.mp_pages = num;
+ }
+
+ return dp;
+}
+
+static size_t
+mdb_leaf_size(MDB_db *db, MDB_val *key, MDB_val *data)
+{
+ size_t sz;
+
+ sz = LEAFSIZE(key, data);
+ if (data->mv_size >= db->md_env->me_head.mh_psize / MDB_MINKEYS) {
+ /* put on overflow page */
+ sz -= data->mv_size - sizeof(pgno_t);
+ }
+
+ return sz + sizeof(indx_t);
+}
+
+static size_t
+mdb_branch_size(MDB_db *db, MDB_val *key)
+{
+ size_t sz;
+
+ sz = INDXSIZE(key);
+ if (sz >= db->md_env->me_head.mh_psize / MDB_MINKEYS) {
+ /* put on overflow page */
+ /* not implemented */
+ /* sz -= key->size - sizeof(pgno_t); */
+ }
+
+ return sz + sizeof(indx_t);
+}
+
+static int
+mdb_add_node(MDB_db *db, MDB_page *mp, indx_t indx,
+ MDB_val *key, MDB_val *data, pgno_t pgno, uint8_t flags)
+{
+ unsigned int i;
+ size_t node_size = NODESIZE;
+ indx_t ofs;
+ MDB_node *node;
+ MDB_dpage *ofp = NULL; /* overflow page */
+
+ assert(mp->mp_upper >= mp->mp_lower);
+
+ DPRINTF("add node [%.*s] to %s page %lu at index %i, key size %zu",
+ key ? (int)key->mv_size : 0, key ? (char *)key->mv_data : NULL,
+ IS_LEAF(mp) ? "leaf" : "branch",
+ mp->mp_pgno, indx, key ? key->mv_size : 0);
+
+ if (key != NULL)
+ node_size += key->mv_size;
+
+ if (IS_LEAF(mp)) {
+ assert(data);
+ node_size += data->mv_size;
+ if (F_ISSET(flags, F_BIGDATA)) {
+ /* Data already on overflow page. */
+ node_size -= data->mv_size - sizeof(pgno_t);
+ } else if (data->mv_size >= db->md_env->me_head.mh_psize / MDB_MINKEYS) {
+ int ovpages = PAGEHDRSZ + data->mv_size + db->md_env->me_head.mh_psize - 1;
+ ovpages /= db->md_env->me_head.mh_psize;
+ /* Put data on overflow page. */
+ DPRINTF("data size is %zu, put on overflow page",
+ data->mv_size);
+ node_size -= data->mv_size - sizeof(pgno_t);
+ if ((ofp = mdbenv_new_page(db->md_env, P_OVERFLOW, ovpages)) == NULL)
+ return MDB_FAIL;
+ DPRINTF("allocated overflow page %lu", ofp->p.mp_pgno);
+ flags |= F_BIGDATA;
+ }
+ }
+
+ if (node_size + sizeof(indx_t) > SIZELEFT(mp)) {
+ DPRINTF("not enough room in page %lu, got %lu ptrs",
+ mp->mp_pgno, NUMKEYS(mp));
+ DPRINTF("upper - lower = %u - %u = %u", mp->mp_upper, mp->mp_lower,
+ mp->mp_upper - mp->mp_lower);
+ DPRINTF("node size = %zu", node_size);
+ return ENOSPC;
+ }
+
+ /* Move higher pointers up one slot. */
+ for (i = NUMKEYS(mp); i > indx; i--)
+ mp->mp_ptrs[i] = mp->mp_ptrs[i - 1];
+
+ /* Adjust free space offsets. */
+ ofs = mp->mp_upper - node_size;
+ assert(ofs >= mp->mp_lower + sizeof(indx_t));
+ mp->mp_ptrs[indx] = ofs;
+ mp->mp_upper = ofs;
+ mp->mp_lower += sizeof(indx_t);
+
+ /* Write the node data. */
+ node = NODEPTR(mp, indx);
+ node->mn_ksize = (key == NULL) ? 0 : key->mv_size;
+ node->mn_flags = flags;
+ if (IS_LEAF(mp))
+ node->mn_dsize = data->mv_size;
+ else
+ node->mn_pgno = pgno;
+
+ if (key)
+ bcopy(key->mv_data, NODEKEY(node), key->mv_size);
+
+ if (IS_LEAF(mp)) {
+ assert(key);
+ if (ofp == NULL) {
+ if (F_ISSET(flags, F_BIGDATA))
+ bcopy(data->mv_data, node->mn_data + key->mv_size,
+ sizeof(pgno_t));
+ else
+ bcopy(data->mv_data, node->mn_data + key->mv_size,
+ data->mv_size);
+ } else {
+ bcopy(&ofp->p.mp_pgno, node->mn_data + key->mv_size,
+ sizeof(pgno_t));
+ bcopy(data->mv_data, METADATA(&ofp->p), data->mv_size);
+ }
+ }
+
+ return MDB_SUCCESS;
+}
+
+static void
+mdb_del_node(MDB_db *db, MDB_page *mp, indx_t indx)
+{
+ unsigned int sz;
+ indx_t i, j, numkeys, ptr;
+ MDB_node *node;
+ char *base;
+
+ DPRINTF("delete node %u on %s page %lu", indx,
+ IS_LEAF(mp) ? "leaf" : "branch", mp->mp_pgno);
+ assert(indx < NUMKEYS(mp));
+
+ node = NODEPTR(mp, indx);
+ sz = NODESIZE + node->mn_ksize;
+ if (IS_LEAF(mp)) {
+ if (F_ISSET(node->mn_flags, F_BIGDATA))
+ sz += sizeof(pgno_t);
+ else
+ sz += NODEDSZ(node);
+ }
+
+ ptr = mp->mp_ptrs[indx];
+ numkeys = NUMKEYS(mp);
+ for (i = j = 0; i < numkeys; i++) {
+ if (i != indx) {
+ mp->mp_ptrs[j] = mp->mp_ptrs[i];
+ if (mp->mp_ptrs[i] < ptr)
+ mp->mp_ptrs[j] += sz;
+ j++;
+ }
+ }
+
+ base = (char *)mp + mp->mp_upper;
+ bcopy(base, base + sz, ptr - mp->mp_upper);
+
+ mp->mp_lower -= sizeof(indx_t);
+ mp->mp_upper += sz;
+}
+
+int
+mdb_cursor_open(MDB_db *db, MDB_txn *txn, MDB_cursor **ret)
+{
+ MDB_cursor *cursor;
+
+ if (db == NULL || ret == NULL)
+ return EINVAL;
+
+ if (txn != NULL && db->md_env != txn->mt_env) {
+ return EINVAL;
+ }
+
+ if ((cursor = calloc(1, sizeof(*cursor))) != NULL) {
+ SLIST_INIT(&cursor->mc_stack);
+ cursor->mc_db = db;
+ cursor->mc_txn = txn;
+ }
+
+ *ret = cursor;
+
+ return MDB_SUCCESS;
+}
+
+void
+mdb_cursor_close(MDB_cursor *cursor)
+{
+ if (cursor != NULL) {
+ while (!CURSOR_EMPTY(cursor))
+ cursor_pop_page(cursor);
+
+/* btree_close(cursor->bt); */
+ free(cursor);
+ }
+}
+
+static int
+mdb_update_key(MDB_db *db, MDB_page *mp, indx_t indx,
+ MDB_val *key)
+{
+ indx_t ptr, i, numkeys;
+ int delta;
+ size_t len;
+ MDB_node *node;
+ char *base;
+
+ node = NODEPTR(mp, indx);
+ ptr = mp->mp_ptrs[indx];
+ DPRINTF("update key %u (ofs %u) [%.*s] to [%.*s] on page %lu",
+ indx, ptr,
+ (int)node->mn_ksize, (char *)NODEKEY(node),
+ (int)key->mv_size, (char *)key->mv_data,
+ mp->mp_pgno);
+
+ delta = key->mv_size - node->mn_ksize;
+ if (delta) {
+ if (delta > 0 && SIZELEFT(mp) < delta) {
+ DPRINTF("OUCH! Not enough room, delta = %d", delta);
+ return ENOSPC;
+ }
+
+ numkeys = NUMKEYS(mp);
+ for (i = 0; i < numkeys; i++) {
+ if (mp->mp_ptrs[i] <= ptr)
+ mp->mp_ptrs[i] -= delta;
+ }
+
+ base = (char *)mp + mp->mp_upper;
+ len = ptr - mp->mp_upper + NODESIZE;
+ bcopy(base, base - delta, len);
+ mp->mp_upper -= delta;
+
+ node = NODEPTR(mp, indx);
+ node->mn_ksize = key->mv_size;
+ }
+
+ bcopy(key->mv_data, NODEKEY(node), key->mv_size);
+
+ return MDB_SUCCESS;
+}
+
+/* Move a node from src to dst.
+ */
+static int
+mdb_move_node(MDB_db *bt, MDB_pageparent *src, indx_t srcindx,
+ MDB_pageparent *dst, indx_t dstindx)
+{
+ int rc;
+ MDB_node *srcnode;
+ MDB_val key, data;
+
+ srcnode = NODEPTR(src->mp_page, srcindx);
+ DPRINTF("moving %s node %u [%.*s] on page %lu to node %u on page %lu",
+ IS_LEAF(src->mp_page) ? "leaf" : "branch",
+ srcindx,
+ (int)srcnode->mn_ksize, (char *)NODEKEY(srcnode),
+ src->mp_page->mp_pgno,
+ dstindx, dst->mp_page->mp_pgno);
+
+ /* Mark src and dst as dirty. */
+ if ((rc = mdb_touch(bt->md_env->me_txn, src)) ||
+ (rc = mdb_touch(bt->md_env->me_txn, dst)))
+ return rc;;
+
+ /* Add the node to the destination page.
+ */
+ key.mv_size = srcnode->mn_ksize;
+ key.mv_data = NODEKEY(srcnode);
+ data.mv_size = NODEDSZ(srcnode);
+ data.mv_data = NODEDATA(srcnode);
+ rc = mdb_add_node(bt, dst->mp_page, dstindx, &key, &data, NODEPGNO(srcnode),
+ srcnode->mn_flags);
+ if (rc != MDB_SUCCESS)
+ return rc;
+
+ /* Delete the node from the source page.
+ */
+ mdb_del_node(bt, src->mp_page, srcindx);
+
+ /* Update the parent separators.
+ */
+ if (srcindx == 0 && src->mp_pi != 0) {
+ DPRINTF("update separator for source page %lu to [%.*s]",
+ src->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
+ if ((rc = mdb_update_key(bt, src->mp_parent, src->mp_pi,
+ &key)) != MDB_SUCCESS)
+ return rc;
+ }
+
+ if (srcindx == 0 && IS_BRANCH(src->mp_page)) {
+ MDB_val nullkey;
+ nullkey.mv_size = 0;
+ assert(mdb_update_key(bt, src->mp_page, 0, &nullkey) == MDB_SUCCESS);
+ }
+
+ if (dstindx == 0 && dst->mp_pi != 0) {
+ DPRINTF("update separator for destination page %lu to [%.*s]",
+ dst->mp_page->mp_pgno, (int)key.mv_size, (char *)key.mv_data);
+ if ((rc = mdb_update_key(bt, dst->mp_parent, dst->mp_pi,
+ &key)) != MDB_SUCCESS)
+ return rc;
+ }
+
+ if (dstindx == 0 && IS_BRANCH(dst->mp_page)) {
+ MDB_val nullkey;
+ nullkey.mv_size = 0;
+ assert(mdb_update_key(bt, dst->mp_page, 0, &nullkey) == MDB_SUCCESS);
+ }
+
+ return MDB_SUCCESS;
+}
+
+static int
+mdb_merge(MDB_db *bt, MDB_pageparent *src, MDB_pageparent *dst)
+{
+ int rc;
+ indx_t i;
+ MDB_node *srcnode;
+ MDB_val key, data;
+ MDB_pageparent mpp;
+ MDB_dhead *dh;
+
+ DPRINTF("merging page %lu and %lu", src->mp_page->mp_pgno, dst->mp_page->mp_pgno);
+
+ assert(src->mp_parent); /* can't merge root page */
+ assert(dst->mp_parent);
+ assert(bt->md_env->me_txn != NULL);
+
+ /* Mark src and dst as dirty. */
+ if ((rc = mdb_touch(bt->md_env->me_txn, src)) ||
+ (rc = mdb_touch(bt->md_env->me_txn, dst)))
+ return rc;
+
+ /* Move all nodes from src to dst.
+ */
+ for (i = 0; i < NUMKEYS(src->mp_page); i++) {
+ srcnode = NODEPTR(src->mp_page, i);
+
+ key.mv_size = srcnode->mn_ksize;
+ key.mv_data = NODEKEY(srcnode);
+ data.mv_size = NODEDSZ(srcnode);
+ data.mv_data = NODEDATA(srcnode);
+ rc = mdb_add_node(bt, dst->mp_page, NUMKEYS(dst->mp_page), &key,
+ &data, NODEPGNO(srcnode), srcnode->mn_flags);
+ if (rc != MDB_SUCCESS)
+ return rc;
+ }
+
+ DPRINTF("dst page %lu now has %lu keys (%.1f%% filled)",
+ dst->mp_page->mp_pgno, NUMKEYS(dst->mp_page), (float)PAGEFILL(bt->md_env, dst->mp_page) / 10);
+
+ /* Unlink the src page from parent.
+ */
+ mdb_del_node(bt, src->mp_parent, src->mp_pi);
+ if (src->mp_pi == 0) {
+ key.mv_size = 0;
+ if ((rc = mdb_update_key(bt, src->mp_parent, 0, &key)) != MDB_SUCCESS)
+ return rc;
+ }
+
+ if (IS_LEAF(src->mp_page))
+ bt->md_env->me_meta.mm_stat.ms_leaf_pages--;
+ else
+ bt->md_env->me_meta.mm_stat.ms_branch_pages--;
+
+ mpp.mp_page = src->mp_parent;
+ dh = (MDB_dhead *)src->mp_parent;
+ dh--;
+ mpp.mp_parent = dh->md_parent;
+ mpp.mp_pi = dh->md_pi;
+
+ return mdb_rebalance(bt, &mpp);
+}
+
+#define FILL_THRESHOLD 250
+
+static int
+mdb_rebalance(MDB_db *db, MDB_pageparent *mpp)
+{
+ MDB_node *node;
+ MDB_page *root;
+ MDB_pageparent npp;
+ indx_t si = 0, di = 0;
+
+ assert(db != NULL);
+ assert(db->md_env->me_txn != NULL);
+ assert(mpp != NULL);
+
+ DPRINTF("rebalancing %s page %lu (has %lu keys, %.1f%% full)",
+ IS_LEAF(mpp->mp_page) ? "leaf" : "branch",
+ mpp->mp_page->mp_pgno, NUMKEYS(mpp->mp_page), (float)PAGEFILL(db->md_env, mpp->mp_page) / 10);
+
+ if (PAGEFILL(db->md_env, mpp->mp_page) >= FILL_THRESHOLD) {
+ DPRINTF("no need to rebalance page %lu, above fill threshold",
+ mpp->mp_page->mp_pgno);
+ return MDB_SUCCESS;
+ }
+
+ if (mpp->mp_parent == NULL) {
+ if (NUMKEYS(mpp->mp_page) == 0) {
+ DPRINTF("tree is completely empty");
+ db->md_env->me_txn->mt_root = P_INVALID;
+ db->md_env->me_meta.mm_stat.ms_depth--;
+ db->md_env->me_meta.mm_stat.ms_leaf_pages--;
+ } else if (IS_BRANCH(mpp->mp_page) && NUMKEYS(mpp->mp_page) == 1) {
+ DPRINTF("collapsing root page!");
+ db->md_env->me_txn->mt_root = NODEPGNO(NODEPTR(mpp->mp_page, 0));
+ if ((root = mdbenv_get_page(db->md_env, db->md_env->me_txn->mt_root)) == NULL)
+ return MDB_FAIL;
+ db->md_env->me_meta.mm_stat.ms_depth--;
+ db->md_env->me_meta.mm_stat.ms_branch_pages--;
+ } else
+ DPRINTF("root page doesn't need rebalancing");
+ return MDB_SUCCESS;
+ }
+
+ /* The parent (branch page) must have at least 2 pointers,
+ * otherwise the tree is invalid.
+ */
+ assert(NUMKEYS(mpp->mp_parent) > 1);
+
+ /* Leaf page fill factor is below the threshold.
+ * Try to move keys from left or right neighbor, or
+ * merge with a neighbor page.
+ */
+
+ /* Find neighbors.
+ */
+ if (mpp->mp_pi == 0) {
+ /* We're the leftmost leaf in our parent.
+ */
+ DPRINTF("reading right neighbor");
+ node = NODEPTR(mpp->mp_parent, mpp->mp_pi + 1);
+ if ((npp.mp_page = mdbenv_get_page(db->md_env, NODEPGNO(node))) == NULL)
+ return MDB_FAIL;
+ npp.mp_pi = mpp->mp_pi + 1;
+ si = 0;
+ di = NUMKEYS(mpp->mp_page);
+ } else {
+ /* There is at least one neighbor to the left.
+ */
+ DPRINTF("reading left neighbor");
+ node = NODEPTR(mpp->mp_parent, mpp->mp_pi - 1);
+ if ((npp.mp_page = mdbenv_get_page(db->md_env, NODEPGNO(node))) == NULL)
+ return MDB_FAIL;
+ npp.mp_pi = mpp->mp_pi - 1;
+ si = NUMKEYS(npp.mp_page) - 1;
+ di = 0;
+ }
+ npp.mp_parent = mpp->mp_parent;
+
+ DPRINTF("found neighbor page %lu (%lu keys, %.1f%% full)",
+ npp.mp_page->mp_pgno, NUMKEYS(npp.mp_page), (float)PAGEFILL(db->md_env, npp.mp_page) / 10);
+
+ /* If the neighbor page is above threshold and has at least two
+ * keys, move one key from it.
+ *
+ * Otherwise we should try to merge them.
+ */
+ if (PAGEFILL(db->md_env, npp.mp_page) >= FILL_THRESHOLD && NUMKEYS(npp.mp_page) >= 2)
+ return mdb_move_node(db, &npp, si, mpp, di);
+ else { /* FIXME: if (has_enough_room()) */
+ if (mpp->mp_pi == 0)
+ return mdb_merge(db, &npp, mpp);
+ else
+ return mdb_merge(db, mpp, &npp);
+ }
+}
+
+int
+mdb_del(MDB_db *bt, MDB_txn *txn,
+ MDB_val *key, MDB_val *data)
+{
+ int rc, exact;
+ unsigned int ki;
+ MDB_node *leaf;
+ MDB_pageparent mpp;
+
+ DPRINTF("========> delete key %.*s", (int)key->mv_size, (char *)key->mv_data);
+
+ assert(key != NULL);
+
+ if (bt == NULL || txn == NULL)
+ return EINVAL;
+
+ if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
+ return EINVAL;
+ }
+
+ if (bt->md_env->me_txn != txn) {
+ return EINVAL;
+ }
+
+ if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
+ return EINVAL;
+ }
+
+ if ((rc = mdb_search_page(bt, txn, key, NULL, 1, &mpp)) != MDB_SUCCESS)
+ return rc;
+
+ leaf = mdb_search_node(bt, mpp.mp_page, key, &exact, &ki);
+ if (leaf == NULL || !exact) {
+ return ENOENT;
+ }
+
+ if (data && (rc = mdb_read_data(bt, NULL, leaf, data)) != MDB_SUCCESS)
+ return rc;
+
+ mdb_del_node(bt, mpp.mp_page, ki);
+ bt->md_env->me_meta.mm_stat.ms_entries--;
+ rc = mdb_rebalance(bt, &mpp);
+ if (rc != MDB_SUCCESS)
+ txn->mt_flags |= MDB_TXN_ERROR;
+
+ return rc;
+}
+
+/* Split page <*mpp>, and insert <key,(data|newpgno)> in either left or
+ * right sibling, at index <*newindxp> (as if unsplit). Updates *mpp and
+ * *newindxp with the actual values after split, ie if *mpp and *newindxp
+ * refer to a node in the new right sibling page.
+ */
+static int
+mdb_split(MDB_db *bt, MDB_page **mpp, unsigned int *newindxp,
+ MDB_val *newkey, MDB_val *newdata, pgno_t newpgno)
+{
+ uint8_t flags;
+ int rc = MDB_SUCCESS, ins_new = 0;
+ indx_t newindx;
+ pgno_t pgno = 0;
+ unsigned int i, j, split_indx;
+ MDB_node *node;
+ MDB_page *pright, *p;
+ MDB_val sepkey, rkey, rdata;
+ MDB_page *copy;
+ MDB_dpage *mdp, *rdp, *pdp;
+ MDB_dhead *dh;
+
+ assert(bt != NULL);
+ assert(bt->md_env != NULL);
+
+ dh = ((MDB_dhead *)*mpp) - 1;
+ mdp = (MDB_dpage *)dh;
+ newindx = *newindxp;
+
+ DPRINTF("-----> splitting %s page %lu and adding [%.*s] at index %i",
+ IS_LEAF(&mdp->p) ? "leaf" : "branch", mdp->p.mp_pgno,
+ (int)newkey->mv_size, (char *)newkey->mv_data, *newindxp);
+
+ if (mdp->h.md_parent == NULL) {
+ if ((pdp = mdbenv_new_page(bt->md_env, P_BRANCH, 1)) == NULL)
+ return MDB_FAIL;
+ mdp->h.md_pi = 0;
+ mdp->h.md_parent = &pdp->p;
+ bt->md_env->me_txn->mt_root = pdp->p.mp_pgno;
+ DPRINTF("root split! new root = %lu", pdp->p.mp_pgno);
+ bt->md_env->me_meta.mm_stat.ms_depth++;
+
+ /* Add left (implicit) pointer. */
+ if (mdb_add_node(bt, &pdp->p, 0, NULL, NULL,
+ mdp->p.mp_pgno, 0) != MDB_SUCCESS)
+ return MDB_FAIL;
+ } else {
+ DPRINTF("parent branch page is %lu", mdp->h.md_parent->mp_pgno);
+ }
+
+ /* Create a right sibling. */
+ if ((rdp = mdbenv_new_page(bt->md_env, mdp->p.mp_flags, 1)) == NULL)
+ return MDB_FAIL;
+ rdp->h.md_parent = mdp->h.md_parent;
+ rdp->h.md_pi = mdp->h.md_pi + 1;
+ DPRINTF("new right sibling: page %lu", rdp->p.mp_pgno);
+
+ /* Move half of the keys to the right sibling. */
+ if ((copy = malloc(bt->md_env->me_head.mh_psize)) == NULL)
+ return MDB_FAIL;
+ bcopy(&mdp->p, copy, bt->md_env->me_head.mh_psize);
+ bzero(&mdp->p.mp_ptrs, bt->md_env->me_head.mh_psize - PAGEHDRSZ);
+ mdp->p.mp_lower = PAGEHDRSZ;
+ mdp->p.mp_upper = bt->md_env->me_head.mh_psize;
+
+ split_indx = NUMKEYS(copy) / 2 + 1;
+
+ /* First find the separating key between the split pages.
+ */
+ bzero(&sepkey, sizeof(sepkey));
+ if (newindx == split_indx) {
+ sepkey.mv_size = newkey->mv_size;
+ sepkey.mv_data = newkey->mv_data;
+ } else {
+ node = NODEPTR(copy, split_indx);
+ sepkey.mv_size = node->mn_ksize;
+ sepkey.mv_data = NODEKEY(node);
+ }
+
+ DPRINTF("separator is [%.*s]", (int)sepkey.mv_size, (char *)sepkey.mv_data);
+
+ /* Copy separator key to the parent.
+ */
+ if (SIZELEFT(rdp->h.md_parent) < mdb_branch_size(bt, &sepkey)) {
+ rc = mdb_split(bt, &rdp->h.md_parent, &rdp->h.md_pi,
+ &sepkey, NULL, rdp->p.mp_pgno);
+
+ /* Right page might now have changed parent.
+ * Check if left page also changed parent.
+ */
+ if (rdp->h.md_parent != mdp->h.md_parent &&
+ mdp->h.md_pi >= NUMKEYS(mdp->h.md_parent)) {
+ mdp->h.md_parent = rdp->h.md_parent;
+ mdp->h.md_pi = rdp->h.md_pi - 1;
+ }
+ } else {
+ rc = mdb_add_node(bt, rdp->h.md_parent, rdp->h.md_pi,
+ &sepkey, NULL, rdp->p.mp_pgno, 0);
+ }
+ if (rc != MDB_SUCCESS) {
+ free(copy);
+ return MDB_FAIL;
+ }
+
+ for (i = j = 0; i <= NUMKEYS(copy); j++) {
+ if (i < split_indx) {
+ /* Re-insert in left sibling. */
+ pdp = mdp;
+ } else {
+ /* Insert in right sibling. */
+ if (i == split_indx)
+ /* Reset insert index for right sibling. */
+ j = (i == newindx && ins_new);
+ pdp = rdp;
+ }
+
+ if (i == newindx && !ins_new) {
+ /* Insert the original entry that caused the split. */
+ rkey.mv_data = newkey->mv_data;
+ rkey.mv_size = newkey->mv_size;
+ if (IS_LEAF(&mdp->p)) {
+ rdata.mv_data = newdata->mv_data;
+ rdata.mv_size = newdata->mv_size;
+ } else
+ pgno = newpgno;
+ flags = 0;
+
+ ins_new = 1;
+
+ /* Update page and index for the new key. */
+ *newindxp = j;
+ *mpp = &pdp->p;
+ } else if (i == NUMKEYS(copy)) {
+ break;
+ } else {
+ node = NODEPTR(copy, i);
+ rkey.mv_data = NODEKEY(node);
+ rkey.mv_size = node->mn_ksize;
+ if (IS_LEAF(&mdp->p)) {
+ rdata.mv_data = NODEDATA(node);
+ rdata.mv_size = node->mn_dsize;
+ } else
+ pgno = node->mn_pgno;
+ flags = node->mn_flags;
+
+ i++;
+ }
+
+ if (!IS_LEAF(&mdp->p) && j == 0) {
+ /* First branch index doesn't need key data. */
+ rkey.mv_size = 0;
+ }
+
+ rc = mdb_add_node(bt, &pdp->p, j, &rkey, &rdata, pgno,flags);
+ }
+
+ free(copy);
+ return rc;
+}
+
+int
+mdb_put(MDB_db *bt, MDB_txn *txn,
+ MDB_val *key, MDB_val *data, unsigned int flags)
+{
+ int rc = MDB_SUCCESS, exact;
+ unsigned int ki;
+ MDB_node *leaf;
+ MDB_pageparent mpp;
+
+ assert(key != NULL);
+ assert(data != NULL);
+
+ if (bt == NULL || txn == NULL)
+ return EINVAL;
+
+ if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
+ return EINVAL;
+ }
+
+ if (bt->md_env->me_txn != txn) {
+ return EINVAL;
+ }
+
+ if (key->mv_size == 0 || key->mv_size > MAXKEYSIZE) {
+ return EINVAL;
+ }
+
+ DPRINTF("==> put key %.*s, size %zu, data size %zu",
+ (int)key->mv_size, (char *)key->mv_data, key->mv_size, data->mv_size);
+
+ rc = mdb_search_page(bt, txn, key, NULL, 1, &mpp);
+ if (rc == MDB_SUCCESS) {
+ leaf = mdb_search_node(bt, mpp.mp_page, key, &exact, &ki);
+ if (leaf && exact) {
+ if (F_ISSET(flags, MDB_NOOVERWRITE)) {
+ DPRINTF("duplicate key %.*s",
+ (int)key->mv_size, (char *)key->mv_data);
+ return EEXIST;
+ }
+ mdb_del_node(bt, mpp.mp_page, ki);
+ }
+ if (leaf == NULL) { /* append if not found */
+ ki = NUMKEYS(mpp.mp_page);
+ DPRINTF("appending key at index %i", ki);
+ }
+ } else if (rc == ENOENT) {
+ MDB_dpage *dp;
+ /* new file, just write a root leaf page */
+ DPRINTF("allocating new root leaf page");
+ if ((dp = mdbenv_new_page(bt->md_env, P_LEAF, 1)) == NULL) {
+ return ENOMEM;
+ }
+ mpp.mp_page = &dp->p;
+ txn->mt_root = mpp.mp_page->mp_pgno;
+ bt->md_env->me_meta.mm_stat.ms_depth++;
+ ki = 0;
+ }
+ else
+ goto done;
+
+ assert(IS_LEAF(mpp.mp_page));
+ DPRINTF("there are %lu keys, should insert new key at index %i",
+ NUMKEYS(mpp.mp_page), ki);
+
+ if (SIZELEFT(mpp.mp_page) < mdb_leaf_size(bt, key, data)) {
+ rc = mdb_split(bt, &mpp.mp_page, &ki, key, data, P_INVALID);
+ } else {
+ /* There is room already in this leaf page. */
+ rc = mdb_add_node(bt, mpp.mp_page, ki, key, data, 0, 0);
+ }
+
+ if (rc != MDB_SUCCESS)
+ txn->mt_flags |= MDB_TXN_ERROR;
+ else
+ bt->md_env->me_meta.mm_stat.ms_entries++;
+
+done:
+ return rc;
+}
+
+static pgno_t
+mdbenv_compact_tree(MDB_env *env, pgno_t pgno, MDB_env *envc)
+{
+ ssize_t rc;
+ indx_t i;
+ pgno_t *pnext, next;
+ MDB_node *node;
+ MDB_page *p;
+ MDB_page *mp;
+
+ /* Get the page and make a copy of it.
+ */
+ if ((mp = mdbenv_get_page(env, pgno)) == NULL)
+ return P_INVALID;
+ if ((p = malloc(env->me_head.mh_psize)) == NULL)
+ return P_INVALID;
+ bcopy(mp, p, env->me_head.mh_psize);
+
+ /* Go through all nodes in the (copied) page and update the
+ * page pointers.
+ */
+ if (F_ISSET(p->mp_flags, P_BRANCH)) {
+ for (i = 0; i < NUMKEYS(p); i++) {
+ node = NODEPTR(p, i);
+ node->mn_pgno = mdbenv_compact_tree(env, node->mn_pgno, envc);
+ if (node->mn_pgno == P_INVALID) {
+ free(p);
+ return P_INVALID;
+ }
+ }
+ } else if (F_ISSET(p->mp_flags, P_LEAF)) {
+ for (i = 0; i < NUMKEYS(p); i++) {
+ node = NODEPTR(p, i);
+ if (F_ISSET(node->mn_flags, F_BIGDATA)) {
+ bcopy(NODEDATA(node), &next, sizeof(next));
+ next = mdbenv_compact_tree(env, next, envc);
+ if (next == P_INVALID) {
+ free(p);
+ return P_INVALID;
+ }
+ bcopy(&next, NODEDATA(node), sizeof(next));
+ }
+ }
+ } else if (F_ISSET(p->mp_flags, P_OVERFLOW)) {
+ ; /* handled below */
+ } else
+ assert(0);
+
+ pgno = p->mp_pgno = envc->me_txn->mt_next_pgno++;
+ rc = write(envc->me_fd, p, env->me_head.mh_psize);
+ free(p);
+ if (rc != (ssize_t)env->me_head.mh_psize)
+ return P_INVALID;
+
+ if (F_ISSET(mp->mp_flags, P_OVERFLOW)) {
+ if (mp->mp_pages > 1) {
+ size_t len = (mp->mp_pages-1) * env->me_head.mh_psize;
+ envc->me_txn->mt_next_pgno += mp->mp_pages-1;
+ rc = write(envc->me_fd, mp+1, len);
+ if (rc != len)
+ return P_INVALID;
+ }
+ }
+ return pgno;
+}
+
+int
+mdbenv_compact(MDB_env *env)
+{
+ char *compact_path = NULL;
+ MDB_env *envc;
+ MDB_txn *txn, *txnc = NULL;
+ int fd, rc;
+ pgno_t root;
+
+ assert(env != NULL);
+
+ if (env->me_path == NULL) {
+ return EINVAL;
+ }
+
+ DPRINTF("compacting mdbenv %p with path %s", env, env->me_path);
+
+ rc = mdb_txn_begin(env, 0, &txn);
+ if (rc) return rc;
+
+ asprintf(&compact_path, "%s.compact.XXXXXX", env->me_path);
+ fd = mkstemp(compact_path);
+ if (fd == -1) {
+ rc = errno;
+ free(compact_path);
+ mdb_txn_abort(txn);
+ return rc;
+ }
+
+ rc = mdbenv_create(&envc, env->me_mapsize);
+ if (rc) goto failed;
+
+ envc->me_fd = fd;
+ rc = mdbenv_open2(envc, env->me_flags);
+ if (rc) goto failed;
+
+ bcopy(&env->me_meta, &envc->me_meta, sizeof(env->me_meta));
+ envc->me_meta.mm_stat.ms_revisions = 0;
+
+ rc = mdb_txn_begin(envc, 0, &txnc);
+ if (rc) goto failed;
+
+ if (env->me_meta.mm_root != P_INVALID) {
+ root = mdbenv_compact_tree(env, env->me_meta.mm_root, envc);
+ if (root == P_INVALID)
+ goto failed;
+ if ((rc = mdbenv_write_meta(envc, root, 0)) != MDB_SUCCESS)
+ goto failed;
+ }
+
+ fsync(fd);
+
+ DPRINTF("renaming %s to %s", compact_path, env->me_path);
+ if (rename(compact_path, env->me_path) != 0) {
+ rc = errno;
+ goto failed;
+ }
+
+ /* Write a "tombstone" meta page so other processes can pick up
+ * the change and re-open the file.
+ */
+ if (mdbenv_write_meta(env, P_INVALID, MDB_TOMBSTONE) != MDB_SUCCESS)
+ goto failed;
+
+ mdb_txn_abort(txn);
+ mdb_txn_abort(txnc);
+ free(compact_path);
+ mdbenv_close(envc);
+ return 0;
+
+failed:
+ mdb_txn_abort(txn);
+ mdb_txn_abort(txnc);
+ unlink(compact_path);
+ free(compact_path);
+ mdbenv_close(envc);
+ return rc;
+}
+
+int
+mdbenv_get_flags(MDB_env *env, unsigned int *arg)
+{
+ if (!env || !arg)
+ return EINVAL;
+
+ *arg = (env->me_flags & ~MDB_FIXPADDING);
+ return MDB_SUCCESS;
+}
+
+int
+mdbenv_get_path(MDB_env *env, const char **arg)
+{
+ if (!env || !arg)
+ return EINVAL;
+
+ *arg = env->me_path;
+ return MDB_SUCCESS;
+}
+
+int
+mdbenv_stat(MDB_env *env, MDB_stat **arg)
+{
+ if (env == NULL || arg == NULL)
+ return EINVAL;
+
+ *arg = &env->me_meta.mm_stat;
+
+ return MDB_SUCCESS;
+}
+
+int mdb_open(MDB_env *env, MDB_txn *txn, const char *name, unsigned int flags, MDB_db **db)
+{
+ if (!name) {
+ *db = (MDB_db *)&env->me_db;
+ return MDB_SUCCESS;
+ }
+ return EINVAL;
+}
+
+int mdb_stat(MDB_db *db, MDB_stat **arg)
+{
+ if (db == NULL || arg == NULL)
+ return EINVAL;
+
+ *arg = &db->md_stat;
+
+ return MDB_SUCCESS;
+}
+
+void mdb_close(MDB_db *db)
+{
+}
projects / openldap / commitdiff