From b7ce06f5c56e452bca6c5a276da7915b8517d80b Mon Sep 17 00:00:00 2001 From: Hallvard Furuseth Date: Wed, 26 Jun 2013 18:02:26 +0200 Subject: [PATCH] Makefile/user-macro comments. --- libraries/liblmdb/Makefile | 33 +++++++++++++++++++++++++++++++++ libraries/liblmdb/mdb.c | 3 +++ 2 files changed, 36 insertions(+) diff --git a/libraries/liblmdb/Makefile b/libraries/liblmdb/Makefile index 7c3903bdff..25c52ada8e 100644 --- a/libraries/liblmdb/Makefile +++ b/libraries/liblmdb/Makefile @@ -1,3 +1,34 @@ +# Makefile for liblmdb (Lightning memory-mapped database library). + +######################################################################## +# Configuration. The compiler options must enable threaded compilation. +# +# Preprocessor macros (for CPPFLAGS) of interest: +# +# To compile successfully if the default does not: +# - MDB_USE_POSIX_SEM (enabled by default on BSD, Apple) +# Define if shared mutexes are unsupported. Note that Posix +# semaphores and shared mutexes have different behaviors and +# different problems, see the Caveats section in lmdb.h. +# +# For best performence or to compile successfully: +# - MDB_DSYNC = "O_DSYNC" (default) or "O_SYNC" (less efficient) +# If O_DSYNC is undefined but exists in /usr/include, +# preferably set some compiler flag to get the definition. +# - MDB_FDATASYNC = "fdatasync" or "fsync" +# Function for flushing the data of a file. Define this to +# "fsync" if fdatasync() is not supported. fdatasync is +# default except on BSD, Apple, Android which use fsync. +# - MDB_USE_PWRITEV +# Define if the pwritev() function is supported. +# +# Data format: +# - MDB_MAXKEYSIZE +# Controls data packing and limits, see mdb.c. +# +# Debugging: +# - MDB_DEBUG, MDB_PARANOID. +# CC = gcc W = -W -Wall -Wno-unused-parameter -Wbad-function-cast OPT = -O2 -g @@ -6,6 +37,8 @@ LDLIBS = SOLIBS = prefix = /usr/local +######################################################################## + IHDRS = lmdb.h ILIBS = liblmdb.a liblmdb.so IPROGS = mdb_stat mdb_copy diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c index c0f43984d6..c4a80add33 100644 --- a/libraries/liblmdb/mdb.c +++ b/libraries/liblmdb/mdb.c @@ -348,6 +348,9 @@ static txnid_t mdb_debug_start; #define MDB_VERSION 1 /** @brief The maximum size of a key in the database. + * + * The library rejects bigger keys, and cannot deal with records + * with bigger keys stored by a library with bigger max keysize. * * We require that keys all fit onto a regular page. This limit * could be raised a bit further if needed; to something just -- 2.39.5