src/util.h


Log

Author Commit Date CI Message
Shawn O. Pearce a7c60cfc 2009-01-03T02:41:26 Add basic support to read pack-*.idx v1 and v2 files The index data is mapped into memory and then scanned using a binary search algorithm to locate the matching entry for the supplied git_oid. The standard fanout hash trick is applied to reduce the search space by 8 iterations. Since the v1 and v2 file formats differ in their search function, due to the different layouts used for the object records, we use two different search implementations and a virtual function pointer to jump to the correct version of code for the current pack index. The single function jump per-pack should be faster then computing a branch point inside the inner loop of a common binary search. To improve concurrency during read operations the pack lock is only held while verifying the index is actually open, or while opening the index for the first time. This permits multiple concurrent readers to scan through the same index. If an invalid index file is opened we close it and mark the git_pack's invalid bit to true. The git_pack structure is kept around in its parent git_packlist, but the invalid bit will cause all future readers to skip over the pack entirely. Pruning the invalid entries is relatively unimportant because they shouldn't be very common, a $GIT_DIRECTORY/objects/pack directory tends to only have valid pack files. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Shawn O. Pearce 2c4b7707 2008-12-31T16:06:48 Add git__fmt as an easier to use snprintf Checking the return value of snprintf is a pain, as it must be >= 0 and < sizeof(buffer). git__fmt is a simple wrapper to perform these checks. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Shawn O. Pearce 9eb79764 2008-12-31T14:35:39 Add string utility functions for prefix and suffix compares Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Shawn O. Pearce 5673434f 2008-12-31T07:34:43 Undefine malloc,strdup,calloc before redefining them Some systems may use cpp macros to define these functions, glibc appears to be one of them. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Shawn O. Pearce 64a47c01 2008-12-30T23:21:36 Wrap malloc and friends and report out of memory as GIT_ENOMEM We now forbid direct use of malloc, strdup or calloc within the library and instead use wrapper functions git__malloc, etc. to invoke the underlying library malloc and set git_errno to a no memory error code if the allocation fails. In the future once we have pack objects in memory we are likely to enhance these routines with garbage collection logic to purge cached pack data when allocations fail. Because the size of the function will grow somewhat large, we don't want to mark them for inline as gcc tends to aggressively inline, creating larger than expected executables. Signed-off-by: Shawn O. Pearce <spearce@spearce.org>
Andreas Ericsson 3a2aabdc 2008-11-22T14:44:47 Add util.h - utility macros ARRAY_SIZE() et al go in util.h, included from common.h Signed-off-by: Andreas Ericsson <ae@op5.se> Signed-off-by: Shawn O. Pearce <spearce@spearce.org>