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author | Sergey Poznyakoff <gray@gnu.org.ua> | 2011-08-10 22:00:34 +0000 |
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committer | Sergey Poznyakoff <gray@gnu.org.ua> | 2011-08-10 22:00:34 +0000 |
commit | 74f7fe561e31637bdbf21aeb817d4a22bbf9c91a (patch) | |
tree | bae9da9f2c749d290ad4f1764dc205bcd23b750e /src/gdbmdefs.h | |
parent | 6b6dcc80555d77858733e44b72e92d1dc60e2c38 (diff) | |
download | gdbm-74f7fe561e31637bdbf21aeb817d4a22bbf9c91a.tar.gz gdbm-74f7fe561e31637bdbf21aeb817d4a22bbf9c91a.tar.bz2 |
Improve memory mapping support.
The new code is more flexible and performs better when
lots of inserts are being made (e.g. when populating the
database with new data).
* src/gdbm.h.in (GDBM_SETMAXMAPSIZE): New constant.
* src/gdbmconst.h (SIZE_T_MAX): New define.
* src/gdbmdefs.h (gdbm_file_info) <cache_size>: Change type
to size_t.
<mmap_inited,mapped_size_max>: New member.
<mapped_remap>: Remove.
* src/gdbmopen.c: Fix a typo.
(gdbm_open): Initialize new members.
(_gdbm_init_cache): Second argument is size_t.
* src/gdbmsetopt.c (gdbm_setopt): Optval argument is void*.
Handle GDBM_SETMAXMAPSIZE.
Improve error checking.
* src/mmap.c (_GDBM_IN_MAPPED_REGION_P): Fix comparison with
the lower bound.
(_GDBM_NEED_REMAP): Return true if mapped_region is NULL.
(SUM_FILE_SIZE): Rewrite.
(_gdbm_mapped_unmap): Don't call msync.
(_gdbm_internal_remap): Take 2 arguments, the second one
giving the new mapped size.
Unmap the region prior to remapping it.
Always pass NULL as the argument to mmap.
(_gdbm_mapped_remap): Rewrite the logic. Change semantics of the
third argument. All uses updated.
(_gdbm_mapped_init): Reflect the above changes.
(_gdbm_mapped_read,_gdbm_mapped_write): Use mmap_inited to decide
whether to use mmap, because mapped_region can be reset to zero
by another functions (namely, _gdbm_mapped_lseek).
Reset mmap_inited to FALSE, if _gdbm_mapped_remap fails.
(_gdbm_mapped_lseek): Rewrite offset computations. Invalidate
the mapped region.
* src/proto.h (_gdbm_init_cache): Change prototype.
* src/update.c (write_header, _gdbm_end_update): Remove checks
for dbf->mapped_region.
* tests/gtload.c: Implement the -maxmap option (set maximal
mapped memory size).
* doc/gdbm.texinfo: Document GDBM_SETMAXMAPSIZE.
Diffstat (limited to 'src/gdbmdefs.h')
-rw-r--r-- | src/gdbmdefs.h | 12 |
1 files changed, 4 insertions, 8 deletions
diff --git a/src/gdbmdefs.h b/src/gdbmdefs.h index 819abbc..2221aa5 100644 --- a/src/gdbmdefs.h +++ b/src/gdbmdefs.h @@ -124,8 +124,6 @@ typedef struct { data_cache_elem ca_data; } cache_elem; - - /* This final structure contains all main memory based information for a gdbm file. This allows multiple gdbm files to be opened at the same time by one program. */ @@ -153,7 +151,8 @@ struct gdbm_file_info { /* Whether or not we're allowing mmap() use. */ unsigned allow_mmap :1; - + unsigned mmap_inited :1; + /* Type of file locking in use. */ enum { LOCKING_NONE = 0, LOCKING_FLOCK, LOCKING_LOCKF, LOCKING_FCNTL } lock_type; @@ -173,7 +172,7 @@ struct gdbm_file_info { /* The bucket cache. */ cache_elem *bucket_cache; - int cache_size; + size_t cache_size; int last_read; /* Points to the current hash bucket in the cache. */ @@ -193,15 +192,12 @@ struct gdbm_file_info { unsigned second_changed :1; /* Mmap info */ + size_t mapped_size_max;/* Max. allowed value for mapped_size */ void *mapped_region; /* Mapped region */ size_t mapped_size; /* Size of the region */ off_t mapped_pos; /* Current offset in the region */ off_t mapped_off; /* Position in the file where the region begins */ - int mapped_remap; /* When set, any call to - _gdbm_mapped_{write|read} will remap the - region according to the above fields. */ - }; /* Now define all the routines in use. */ |