Use IDL2 for dirty page list

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 26712a8455f428d7553791f03005e68b2f178f81..6faa1f5bdd5ecfffe1e80d45839583f803188be1 100644 (file)
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -203,7 +203,6 @@ typedef struct MDB_meta {                   /* meta (footer) page content */
 } MDB_meta;
 
 typedef struct MDB_dhead {                                     /* a dirty page */
-       STAILQ_ENTRY(MDB_dpage)  md_next;       /* queue of dirty pages */
        MDB_page        *md_parent;
        unsigned        md_pi;                          /* parent index */
        int                     md_num;
@@ -214,8 +213,6 @@ typedef struct MDB_dpage {
        MDB_page        p;
 } MDB_dpage;
 
-STAILQ_HEAD(dirty_queue, MDB_dpage);   /* FIXME: use a sorted data structure */
-
 typedef struct MDB_oldpages {
        struct MDB_oldpages *mo_next;
        ULONG           mo_txnid;
@@ -289,7 +286,7 @@ struct MDB_txn {
        MDB_env         *mt_env;        
        pgno_t          *mt_free_pgs;   /* this is an IDL */
        union {
-               struct dirty_queue      *dirty_queue;   /* modified pages */
+               MIDL2   *dirty_list;    /* modified pages */
                MDB_reader      *reader;
        } mt_u;
        MDB_dbx         *mt_dbxs;               /* array */
@@ -333,6 +330,7 @@ struct MDB_env {
        MDB_oldpages *me_pghead;
        pthread_key_t   me_txkey;       /* thread-key for readers */
        pgno_t          me_free_pgs[MDB_IDL_UM_SIZE];
+       MIDL2           me_dirty_list[MDB_IDL_DB_SIZE];
 };
 
 #define NODESIZE        offsetof(MDB_node, mn_data)
@@ -483,6 +481,7 @@ mdb_alloc_page(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num)
        MDB_dpage *dp;
        pgno_t pgno = P_INVALID;
        ULONG oldest;
+       MIDL2 mid;
 
        if (txn->mt_txnid > 2) {
 
@@ -574,13 +573,15 @@ mdb_alloc_page(MDB_txn *txn, MDB_page *parent, unsigned int parent_idx, int num)
        dp->h.md_num = num;
        dp->h.md_parent = parent;
        dp->h.md_pi = parent_idx;
-       STAILQ_INSERT_TAIL(txn->mt_u.dirty_queue, dp, h.md_next);
        if (pgno == P_INVALID) {
                dp->p.mp_pgno = txn->mt_next_pgno;
                txn->mt_next_pgno += num;
        } else {
                dp->p.mp_pgno = pgno;
        }
+       mid.mid = dp->p.mp_pgno;
+       mid.mptr = dp;
+       mdb_midl2_insert(txn->mt_u.dirty_list, &mid);
 
        return dp;
 }
@@ -640,17 +641,13 @@ mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
        if (rdonly) {
                txn->mt_flags |= MDB_TXN_RDONLY;
        } else {
-               txn->mt_u.dirty_queue = calloc(1, sizeof(*txn->mt_u.dirty_queue));
-               if (txn->mt_u.dirty_queue == NULL) {
-                       free(txn);
-                       return ENOMEM;
-               }
-               STAILQ_INIT(txn->mt_u.dirty_queue);
+               txn->mt_u.dirty_list = env->me_dirty_list;
+               txn->mt_u.dirty_list[0].mid = 0;
+               txn->mt_free_pgs = env->me_free_pgs;
+               txn->mt_free_pgs[0] = 0;
 
                pthread_mutex_lock(&env->me_txns->mti_wmutex);
                env->me_txns->mti_txnid++;
-               txn->mt_free_pgs = env->me_free_pgs;
-               txn->mt_free_pgs[0] = 0;
        }
 
        txn->mt_txnid = env->me_txns->mti_txnid;
@@ -712,7 +709,6 @@ mdb_txn_begin(MDB_env *env, int rdonly, MDB_txn **ret)
 void
 mdb_txn_abort(MDB_txn *txn)
 {
-       MDB_dpage *dp;
        MDB_env *env;
 
        if (txn == NULL)
@@ -731,12 +727,8 @@ mdb_txn_abort(MDB_txn *txn)
                unsigned int i;
 
                /* Discard all dirty pages. */
-               while (!STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
-                       dp = STAILQ_FIRST(txn->mt_u.dirty_queue);
-                       STAILQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
-                       free(dp);
-               }
-               free(txn->mt_u.dirty_queue);
+               for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++)
+                       free(txn->mt_u.dirty_list[i].mptr);
 
                while ((mop = txn->mt_env->me_pghead)) {
                        txn->mt_env->me_pghead = mop->mo_next;
@@ -788,7 +780,7 @@ mdb_txn_commit(MDB_txn *txn)
                return EINVAL;
        }
 
-       if (STAILQ_EMPTY(txn->mt_u.dirty_queue))
+       if (!txn->mt_u.dirty_list[0].mid)
                goto done;
 
        DPRINTF("committing transaction %lu on mdbenv %p, root page %lu",
@@ -861,7 +853,8 @@ mdb_txn_commit(MDB_txn *txn)
                n = 0;
                done = 1;
                size = 0;
-               STAILQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
+               for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++) {
+                       dp = txn->mt_u.dirty_list[i].mptr;
                        if (dp->p.mp_pgno != next) {
                                if (n) {
                                        DPRINTF("committing %u dirty pages", n);
@@ -913,11 +906,8 @@ mdb_txn_commit(MDB_txn *txn)
 
        /* Drop the dirty pages.
         */
-       while (!STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
-               dp = STAILQ_FIRST(txn->mt_u.dirty_queue);
-               STAILQ_REMOVE_HEAD(txn->mt_u.dirty_queue, h.md_next);
-               free(dp);
-       }
+       for (i=1; i<=txn->mt_u.dirty_list[0].mid; i++)
+               free(txn->mt_u.dirty_list[i].mptr);
 
        if ((n = mdb_env_sync(env, 0)) != 0 ||
            (n = mdb_env_write_meta(txn)) != MDB_SUCCESS) {
@@ -948,7 +938,6 @@ mdb_txn_commit(MDB_txn *txn)
        }
 
        pthread_mutex_unlock(&env->me_txns->mti_wmutex);
-       free(txn->mt_u.dirty_queue);
        free(txn);
        txn = NULL;
 
@@ -1529,14 +1518,16 @@ mdb_get_page(MDB_txn *txn, pgno_t pgno)
        MDB_page *p = NULL;
        int found = 0;
 
-       if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && !STAILQ_EMPTY(txn->mt_u.dirty_queue)) {
+       if (!F_ISSET(txn->mt_flags, MDB_TXN_RDONLY) && txn->mt_u.dirty_list[0].mid) {
                MDB_dpage *dp;
-               STAILQ_FOREACH(dp, txn->mt_u.dirty_queue, h.md_next) {
-                       if (dp->p.mp_pgno == pgno) {
-                               p = &dp->p;
-                               found = 1;
-                               break;
-                       }
+               MIDL2 id;
+               unsigned x;
+               id.mid = pgno;
+               x = mdb_midl2_search(txn->mt_u.dirty_list, &id);
+               if (x <= txn->mt_u.dirty_list[0].mid && txn->mt_u.dirty_list[x].mid == pgno) {
+                       dp = txn->mt_u.dirty_list[x].mptr;
+                       p = &dp->p;
+                       found = 1;
                }
        }
        if (!found) {

diff --git a/libraries/libmdb/midl.c b/libraries/libmdb/midl.c
index 8b39acad6509f78e9576101ef3a698ce9befb522..136798f75f2f2204349a371e63c4218229b526d1 100644 (file)
--- a/libraries/libmdb/midl.c
+++ b/libraries/libmdb/midl.c
@@ -24,6 +24,9 @@ typedef unsigned long pgno_t;
 /* Sort the IDLs from highest to lowest */
 #define IDL_CMP(x,y)    ( x > y ? -1 : ( x < y ? 1 : 0 ) )
 
+/* Sort the IDL2s from lowest to highest */
+#define IDL2_CMP(x,y)   ( x < y ? -1 : ( x > y ? 1 : 0 ) )
+
 unsigned mdb_midl_search( ID *ids, ID id )
 {
        /*
@@ -62,7 +65,7 @@ unsigned mdb_midl_search( ID *ids, ID id )
 
 int mdb_midl_insert( ID *ids, ID id )
 {
-       unsigned x;
+       unsigned x, i;
 
        if (MDB_IDL_IS_RANGE( ids )) {
                /* if already in range, treat as a dup */
@@ -101,9 +104,78 @@ int mdb_midl_insert( ID *ids, ID id )
        
        } else {
                /* insert id */
-               AC_MEMCPY( &ids[x+1], &ids[x], (ids[0]-x) * sizeof(ID) );
+               for (i=ids[0]; i>x; i--)
+                       ids[i] = ids[i-1];
                ids[x] = id;
        }
 
        return 0;
 }
+
+unsigned mdb_midl2_search( MIDL2 *ids, MIDL2 *id )
+{
+       /*
+        * binary search of id in ids
+        * if found, returns position of id
+        * if not found, returns first position greater than id
+        */
+       unsigned base = 0;
+       unsigned cursor = 0;
+       int val = 0;
+       unsigned n = ids[0].mid;
+
+       while( 0 < n ) {
+               int pivot = n >> 1;
+               cursor = base + pivot;
+               val = IDL2_CMP( id->mid, ids[cursor + 1].mid );
+
+               if( val < 0 ) {
+                       n = pivot;
+
+               } else if ( val > 0 ) {
+                       base = cursor + 1;
+                       n -= pivot + 1;
+
+               } else {
+                       return cursor + 1;
+               }
+       }
+
+       if( val > 0 ) {
+               return cursor + 2;
+       } else {
+               return cursor + 1;
+       }
+}
+
+int mdb_midl2_insert( MIDL2 *ids, MIDL2 *id )
+{
+       unsigned x, i;
+
+       x = mdb_midl2_search( ids, id );
+       assert( x > 0 );
+
+       if( x < 1 ) {
+               /* internal error */
+               return -2;
+       }
+
+       if ( x <= ids[0].mid && ids[x].mid == id->mid ) {
+               /* duplicate */
+               return -1;
+       }
+
+       if ( ids[0].mid >= MDB_IDL_DB_MAX ) {
+               /* too big */
+               return -2;
+
+       } else {
+               /* insert id */
+               ids[0].mid++;
+               for (i=ids[0].mid; i>x; i--)
+                       ids[i] = ids[i-1];
+               ids[x] = *id;
+       }
+
+       return 0;
+}

diff --git a/libraries/libmdb/midl.h b/libraries/libmdb/midl.h
index 71d006216f09c66e9594c3b3ba37007708296c18..479545f404b7727e8a030fc2c81506e19181845b 100644 (file)
--- a/libraries/libmdb/midl.h
+++ b/libraries/libmdb/midl.h
@@ -75,4 +75,12 @@
 
 int mdb_midl_insert( ID *ids, ID id );
 
+typedef struct MIDL2 {
+       ID mid;
+       void *mptr;
+} MIDL2;
+
+unsigned mdb_midl2_search( MIDL2 *ids, MIDL2 *id );
+int mdb_midl2_insert( MIDL2 *ids, MIDL2 *id );
+
 #endif /* _MDB_MIDL_H_ */