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2021-08-25use xopen() to handle fatal open(2) failuresLibravatar René Scharfe1-6/+2
Add and apply a semantic patch for using xopen() instead of calling open(2) and die() or die_errno() explicitly. This makes the error messages more consistent and shortens the code. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-04-08Merge branch 'tb/reverse-midx'Libravatar Junio C Hamano1-11/+25
An on-disk reverse-index to map the in-pack location of an object back to its object name across multiple packfiles is introduced. * tb/reverse-midx: midx.c: improve cache locality in midx_pack_order_cmp() pack-revindex: write multi-pack reverse indexes pack-write.c: extract 'write_rev_file_order' pack-revindex: read multi-pack reverse indexes Documentation/technical: describe multi-pack reverse indexes midx: make some functions non-static midx: keep track of the checksum midx: don't free midx_name early midx: allow marking a pack as preferred t/helper/test-read-midx.c: add '--show-objects' builtin/multi-pack-index.c: display usage on unrecognized command builtin/multi-pack-index.c: don't enter bogus cmd_mode builtin/multi-pack-index.c: split sub-commands builtin/multi-pack-index.c: define common usage with a macro builtin/multi-pack-index.c: don't handle 'progress' separately builtin/multi-pack-index.c: inline 'flags' with options
2021-04-01pack-write.c: extract 'write_rev_file_order'Libravatar Taylor Blau1-11/+25
Existing callers provide the reverse index code with an array of 'struct pack_idx_entry *'s, which is then sorted by pack order (comparing the offsets of each object within the pack). Prepare for the multi-pack index to write a .rev file by providing a way to write the reverse index without an array of pack_idx_entry (which the MIDX code does not have). Instead, callers can invoke 'write_rev_index_positions()', which takes an array of uint32_t's. The ith entry in this array specifies the ith object's (in index order) position within the pack (in pack order). Expose this new function for use in a later patch, and rewrite the existing write_rev_file() in terms of this new function. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-03-01Merge branch 'jt/transfer-fsck-across-packs'Libravatar Junio C Hamano1-1/+7
The approach to "fsck" the incoming objects in "index-pack" is attractive for performance reasons (we have them already in core, inflated and ready to be inspected), but fundamentally cannot be applied fully when we receive more than one pack stream, as a tree object in one pack may refer to a blob object in another pack as ".gitmodules", when we want to inspect blobs that are used as ".gitmodules" file, for example. Teach "index-pack" to emit objects that must be inspected later and check them in the calling "fetch-pack" process. * jt/transfer-fsck-across-packs: fetch-pack: print and use dangling .gitmodules fetch-pack: with packfile URIs, use index-pack arg http-fetch: allow custom index-pack args http: allow custom index-pack args
2021-02-22fetch-pack: print and use dangling .gitmodulesLibravatar Jonathan Tan1-1/+7
Teach index-pack to print dangling .gitmodules links after its "keep" or "pack" line instead of declaring an error, and teach fetch-pack to check such lines printed. This allows the tree side of the .gitmodules link to be in one packfile and the blob side to be in another without failing the fsck check, because it is now fetch-pack which checks such objects after all packfiles have been downloaded and indexed (and not index-pack on an individual packfile, as it is before this commit). Signed-off-by: Jonathan Tan <jonathantanmy@google.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-25pack-write.c: prepare to write 'pack-*.rev' filesLibravatar Taylor Blau1-1/+119
This patch prepares for callers to be able to write reverse index files to disk. It adds the necessary machinery to write a format-compliant .rev file from within 'write_rev_file()', which is called from 'finish_tmp_packfile()'. Similar to the process by which the reverse index is computed in memory, these new paths also have to sort a list of objects by their offsets within a packfile. These new paths use a qsort() (as opposed to a radix sort), since our specialized radix sort requires a full revindex_entry struct per object, which is more memory than we need to allocate. The qsort is obviously slower, but the theoretical slowdown would require a repository with a large amount of objects, likely implying that the time spent in, say, pack-objects during a repack would dominate the overall runtime. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-14pack-write: die on error in write_promisor_file()Libravatar Christian Couder1-2/+6
write_promisor_file() already uses xfopen(), so it would die if the file cannot be opened for writing. To be consistent with this behavior and not overlook issues, let's also die if there are errors when we are actually writing to the file. Suggested-by: Jeff King <peff@peff.net> Suggested-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-01-12fetch-pack: refactor writing promisor fileLibravatar Christian Couder1-0/+12
Let's replace the 2 different pieces of code that write a promisor file in 'builtin/repack.c' and 'fetch-pack.c' with a new function called 'write_promisor_file()' in 'pack-write.c' and 'pack.h'. This might also help us in the future, if we want to put back the ref names and associated hashes that were in the promisor files we are repacking in 'builtin/repack.c' as suggested by a NEEDSWORK comment just above the code we are refactoring. Signed-off-by: Christian Couder <chriscool@tuxfamily.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-25Merge branch 'rs/hashwrite-be64'Libravatar Junio C Hamano1-4/+1
Code simplification. * rs/hashwrite-be64: pack-write: use hashwrite_be64() midx: use hashwrite_be64() csum-file: add hashwrite_be64()
2020-11-12pack-write: use hashwrite_be64()Libravatar René Scharfe1-4/+1
Call hashwrite_be64() to write a 64-bit value instead of open-coding it using htonl() and hashwrite(). This shortens the code, gets rid of a buffer and several magic numbers, and makes the intent clearer. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-11-01pack-write: use hashwrite_be32() instead of double-buffering arrayLibravatar René Scharfe1-3/+1
hashwrite() already buffers writes, so pass the fanout table entries individually via hashwrite_be32(), which also does the endianess conversion for us. This avoids a memory copy, shortens the code and reduces the number of magic numbers. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-09-19pack-write: use hashwrite_be32() in write_idx_file()Libravatar René Scharfe1-8/+4
Call hashwrite_be32() instead of open-coding it. This shortens the code a bit and makes it easier to read. Signed-off-by: René Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2020-07-30Merge branch 'jb/doc-packfile-name' into masterLibravatar Junio C Hamano1-3/+2
Doc update. * jb/doc-packfile-name: pack-write/docs: update regarding pack naming
2020-07-22pack-write/docs: update regarding pack namingLibravatar Johannes Berg1-3/+2
The index-pack documentation explicitly states that the pack name is derived from the sorted list of object names, but since commit 1190a1acf800 ("pack-objects: name pack files after trailer hash") that isn't true anymore. Be less explicit in the docs as to what the exact output is, and just say that it's whatever goes into the pack name. Also update a comment on write_idx_file() since it no longer modifies the sha1 variable (it's const now anyway), as noted by Junio. Fixes: 1190a1acf800 ("pack-objects: name pack files after trailer hash") Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2019-08-19pack-write: use hash_to_hex when writing checksumsLibravatar brian m. carlson1-4/+4
Pack checksums always use the current hash algorithm in use, so switch from sha1_to_hex to hash_to_hex. Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29convert "hashcmp() != 0" to "!hasheq()"Libravatar Jeff King1-1/+1
This rounds out the previous three patches, covering the inequality logic for the "hash" variant of the functions. As with the previous three, the accompanying code changes are the mechanical result of applying the coccinelle patch; see those patches for more discussion. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-08-29convert "oidcmp() == 0" to oideq()Libravatar Jeff King1-1/+1
Using the more restrictive oideq() should, in the long run, give the compiler more opportunities to optimize these callsites. For now, this conversion should be a complete noop with respect to the generated code. The result is also perhaps a little more readable, as it avoids the "zero is equal" idiom. Since it's so prevalent in C, I think seasoned programmers tend not to even notice it anymore, but it can sometimes make for awkward double negations (e.g., we can drop a few !!oidcmp() instances here). This patch was generated almost entirely by the included coccinelle patch. This mechanical conversion should be completely safe, because we check explicitly for cases where oidcmp() is compared to 0, which is what oideq() is doing under the hood. Note that we don't have to catch "!oidcmp()" separately; coccinelle's standard isomorphisms make sure the two are treated equivalently. I say "almost" because I did hand-edit the coccinelle output to fix up a few style violations (it mostly keeps the original formatting, but sometimes unwraps long lines). Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-02csum-file: refactor finalize_hashfile() methodLibravatar Derrick Stolee1-2/+3
If we want to use a hashfile on the temporary file for a lockfile, then we need finalize_hashfile() to fully write the trailing hash but also keep the file descriptor open. Do this by adding a new CSUM_HASH_IN_STREAM flag along with a functional change that checks this flag before writing the checksum to the stream. This differs from previous behavior since it would be written if either CSUM_CLOSE or CSUM_FSYNC is provided. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-04-02csum-file: rename hashclose() to finalize_hashfile()Libravatar Derrick Stolee1-2/+2
The hashclose() method behaves very differently depending on the flags parameter. In particular, the file descriptor is not always closed. Perform a simple rename of "hashclose()" to "finalize_hashfile()" in preparation for functional changes. Signed-off-by: Derrick Stolee <dstolee@microsoft.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-02csum-file: rename sha1file to hashfileLibravatar brian m. carlson1-16/+16
Rename struct sha1file to struct hashfile, along with all of its related functions. The transformation in this commit was made by global search-and-replace. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-02-02pack-write: switch various SHA-1 values to abstract formsLibravatar brian m. carlson1-24/+25
Convert various uses of hardcoded 20- and 40-based numbers to use the_hash_algo, along with direct calls to SHA-1. Adjust the names of variables to refer to "hash" instead of "sha1". Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-27avoid looking at errno for short read_in_full() returnsLibravatar Jeff King1-1/+6
When a caller tries to read a particular set of bytes via read_in_full(), there are three possible outcomes: 1. An error, in which case -1 is returned and errno is set. 2. A short read, in which fewer bytes are returned and errno is unspecified (we never saw a read error, so we may have some random value from whatever syscall failed last). 3. The full read completed successfully. Many callers handle cases 1 and 2 together by just checking the result against the requested size. If their combined error path looks at errno (e.g., by calling die_errno), they may report a nonsense value. Let's fix these sites by having them distinguish between the two error cases. That avoids the random errno confusion, and lets us give more detailed error messages. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08pack: convert struct pack_idx_entry to struct object_idLibravatar brian m. carlson1-5/+5
Convert struct pack_idx_entry to use struct object_id by changing the definition and applying the following semantic patch, plus the standard object_id transforms: @@ struct pack_idx_entry E1; @@ - E1.sha1 + E1.oid.hash @@ struct pack_idx_entry *E1; @@ - E1->sha1 + E1->oid.hash Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-28odb_mkstemp: write filename into strbufLibravatar Jeff King1-6/+6
The odb_mkstemp() function expects the caller to provide a fixed buffer to write the resulting tempfile name into. But it creates the template using snprintf without checking the return value. This means we could silently truncate the filename. In practice, it's unlikely that the truncation would end in the template-pattern that mkstemp needs to open the file. So we'd probably end up failing either way, unless the path was specially crafted. The simplest fix would be to notice the truncation and die. However, we can observe that most callers immediately xstrdup() the result anyway. So instead, let's switch to using a strbuf, which is easier for them (and isn't a big deal for the other 2 callers, who can just strbuf_release when they're done with it). Note that many of the callers used static buffers, but this was purely to avoid putting a large buffer on the stack. We never passed the static buffers out of the function, so there's no complicated memory handling we need to change. Signed-off-by: Jeff King <peff@peff.net>
2017-03-28do not check odb_mkstemp return value for errorsLibravatar Jeff King1-2/+2
The odb_mkstemp function does not return an error; it dies on failure instead. But many of its callers compare the resulting descriptor against -1 and die themselves. Mostly this is just pointless, but it does raise a question when looking at the callers: if they show the results of the "template" buffer after a failure, what's in it? The answer is: it doesn't matter, because it cannot happen. So let's make that clear by removing the bogus error checks. In bitmap_writer_finish(), we can drop the error-handling code entirely. In the other two cases, it's shared with the open() in another code path; we can just move the error-check next to that open() call. And while we're at it, let's flesh out the function's docstring a bit to make the error behavior clear. Signed-off-by: Jeff King <peff@peff.net>
2017-03-24encode_in_pack_object_header: respect output buffer lengthLibravatar Jeff King1-1/+4
The encode_in_pack_object_header() writes a variable-length header to an output buffer, but it doesn't actually know long the buffer is. At first glance, this looks like it might be possible to overflow. In practice, this is probably impossible. The smallest buffer we use is 10 bytes, which would hold the header for an object up to 2^67 bytes. Obviously we're not likely to see such an object, but we might worry that an object could lie about its size (causing us to overflow before we realize it does not actually have that many bytes). But the argument is passed as a uintmax_t. Even on systems that have __int128 available, uintmax_t is typically restricted to 64-bit by the ABI. So it's unlikely that a system exists where this could be exploited. Still, it's easy enough to use a normal out/len pair and make sure we don't write too far. That protects the hypothetical 128-bit system, makes it harder for callers to accidentally specify a too-small buffer, and makes the resulting code easier to audit. Note that the one caller in fast-import tried to catch such a case, but did so _after_ the call (at which point we'd have already overflowed!). This check can now go away. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-29use QSORTLibravatar René Scharfe1-2/+1
Apply the semantic patch contrib/coccinelle/qsort.cocci to the code base, replacing calls of qsort(3) with QSORT. The resulting code is shorter and supports empty arrays with NULL pointers. Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-29sha1_file: drop free_pack_by_nameLibravatar Jeff King1-1/+0
The point of this function is to drop an entry from the "packed_git" cache that points to a file we might be overwriting, because our contents may not be the same (and hence the only caller was pack-objects as it moved a temporary packfile into place). In older versions of git, this could happen because the names of packfiles were derived from the set of objects they contained, not the actual bits on disk. But since 1190a1a (pack-objects: name pack files after trailer hash, 2013-12-05), the name reflects the actual bits on disk, and any two packfiles with the same name can be used interchangeably. Dropping this function not only saves a few lines of code, it makes the lifetime of "struct packed_git" much easier to reason about: namely, we now do not ever free these structs. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-09-02pack-write: simplify index_pack_lockfile using skip_prefix() and xstrfmt()Libravatar René Scharfe1-6/+5
Get rid of magic string length constants by using skip_prefix() instead of memcmp() and use xstrfmt() for building a string instead of a PATH_MAX-sized buffer, snprintf() and xstrdup(). Signed-off-by: Rene Scharfe <l.s.r@web.de> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-03-03finish_tmp_packfile():use strbuf for pathname constructionLibravatar Sun He1-8/+10
The old version fixes a maximum length on the buffer, which could be a problem if one is not certain of the length of get_object_directory(). Using strbuf can avoid the protential bug. Helped-by: Michael Haggerty <mhagger@alum.mit.edu> Helped-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Sun He <sunheehnus@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2014-02-27Merge branch 'jk/pack-bitmap'Libravatar Junio C Hamano1-0/+2
Borrow the bitmap index into packfiles from JGit to speed up enumeration of objects involved in a commit range without having to fully traverse the history. * jk/pack-bitmap: (26 commits) ewah: unconditionally ntohll ewah data ewah: support platforms that require aligned reads read-cache: use get_be32 instead of hand-rolled ntoh_l block-sha1: factor out get_be and put_be wrappers do not discard revindex when re-preparing packfiles pack-bitmap: implement optional name_hash cache t/perf: add tests for pack bitmaps t: add basic bitmap functionality tests count-objects: recognize .bitmap in garbage-checking repack: consider bitmaps when performing repacks repack: handle optional files created by pack-objects repack: turn exts array into array-of-struct repack: stop using magic number for ARRAY_SIZE(exts) pack-objects: implement bitmap writing rev-list: add bitmap mode to speed up object lists pack-objects: use bitmaps when packing objects pack-objects: split add_object_entry pack-bitmap: add support for bitmap indexes documentation: add documentation for the bitmap format ewah: compressed bitmap implementation ...
2014-01-10Merge branch 'jk/sha1write-void'Libravatar Junio C Hamano1-2/+1
Code clean-up. * jk/sha1write-void: do not pretend sha1write returns errors
2013-12-30pack-objects: implement bitmap writingLibravatar Vicent Marti1-0/+2
This commit extends more the functionality of `pack-objects` by allowing it to write out a `.bitmap` index next to any written packs, together with the `.idx` index that currently gets written. If bitmap writing is enabled for a given repository (either by calling `pack-objects` with the `--write-bitmap-index` flag or by having `pack.writebitmaps` set to `true` in the config) and pack-objects is writing a packfile that would normally be indexed (i.e. not piping to stdout), we will attempt to write the corresponding bitmap index for the packfile. Bitmap index writing happens after the packfile and its index has been successfully written to disk (`finish_tmp_packfile`). The process is performed in several steps: 1. `bitmap_writer_set_checksum`: this call stores the partial checksum for the packfile being written; the checksum will be written in the resulting bitmap index to verify its integrity 2. `bitmap_writer_build_type_index`: this call uses the array of `struct object_entry` that has just been sorted when writing out the actual packfile index to disk to generate 4 type-index bitmaps (one for each object type). These bitmaps have their nth bit set if the given object is of the bitmap's type. E.g. the nth bit of the Commits bitmap will be 1 if the nth object in the packfile index is a commit. This is a very cheap operation because the bitmap writing code has access to the metadata stored in the `struct object_entry` array, and hence the real type for each object in the packfile. 3. `bitmap_writer_reuse_bitmaps`: if there exists an existing bitmap index for one of the packfiles we're trying to repack, this call will efficiently rebuild the existing bitmaps so they can be reused on the new index. All the existing bitmaps will be stored in a `reuse` hash table, and the commit selection phase will prioritize these when selecting, as they can be written directly to the new index without having to perform a revision walk to fill the bitmap. This can greatly speed up the repack of a repository that already has bitmaps. 4. `bitmap_writer_select_commits`: if bitmap writing is enabled for a given `pack-objects` run, the sequence of commits generated during the Counting Objects phase will be stored in an array. We then use that array to build up the list of selected commits. Writing a bitmap in the index for each object in the repository would be cost-prohibitive, so we use a simple heuristic to pick the commits that will be indexed with bitmaps. The current heuristics are a simplified version of JGit's original implementation. We select a higher density of commits depending on their age: the 100 most recent commits are always selected, after that we pick 1 commit of each 100, and the gap increases as the commits grow older. On top of that, we make sure that every single branch that has not been merged (all the tips that would be required from a clone) gets their own bitmap, and when selecting commits between a gap, we tend to prioritize the commit with the most parents. Do note that there is no right/wrong way to perform commit selection; different selection algorithms will result in different commits being selected, but there's no such thing as "missing a commit". The bitmap walker algorithm implemented in `prepare_bitmap_walk` is able to adapt to missing bitmaps by performing manual walks that complete the bitmap: the ideal selection algorithm, however, would select the commits that are more likely to be used as roots for a walk in the future (e.g. the tips of each branch, and so on) to ensure a bitmap for them is always available. 5. `bitmap_writer_build`: this is the computationally expensive part of bitmap generation. Based on the list of commits that were selected in the previous step, we perform several incremental walks to generate the bitmap for each commit. The walks begin from the oldest commit, and are built up incrementally for each branch. E.g. consider this dag where A, B, C, D, E, F are the selected commits, and a, b, c, e are a chunk of simplified history that will not receive bitmaps. A---a---B--b--C--c--D \ E--e--F We start by building the bitmap for A, using A as the root for a revision walk and marking all the objects that are reachable until the walk is over. Once this bitmap is stored, we reuse the bitmap walker to perform the walk for B, assuming that once we reach A again, the walk will be terminated because A has already been SEEN on the previous walk. This process is repeated for C, and D, but when we try to generate the bitmaps for E, we can reuse neither the current walk nor the bitmap we have generated so far. What we do now is resetting both the walk and clearing the bitmap, and performing the walk from scratch using E as the origin. This new walk, however, does not need to be completed. Once we hit B, we can lookup the bitmap we have already stored for that commit and OR it with the existing bitmap we've composed so far, allowing us to limit the walk early. After all the bitmaps have been generated, another iteration through the list of commits is performed to find the best XOR offsets for compression before writing them to disk. Because of the incremental nature of these bitmaps, XORing one of them with its predecesor results in a minimal "bitmap delta" most of the time. We can write this delta to the on-disk bitmap index, and then re-compose the original bitmaps by XORing them again when loaded. This is a phase very similar to pack-object's `find_delta` (using bitmaps instead of objects, of course), except the heuristics have been greatly simplified: we only check the 10 bitmaps before any given one to find best compressing one. This gives good results in practice, because there is locality in the ordering of the objects (and therefore bitmaps) in the packfile. 6. `bitmap_writer_finish`: the last step in the process is serializing to disk all the bitmap data that has been generated in the two previous steps. The bitmap is written to a tmp file and then moved atomically to its final destination, using the same process as `pack-write.c:write_idx_file`. Signed-off-by: Vicent Marti <tanoku@gmail.com> Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-26do not pretend sha1write returns errorsLibravatar Jeff King1-2/+1
The sha1write function returns an int, but it will always be "0". The failure-prone parts of the function happen in the "flush" callback, which cannot pass an error back to us. So we just end up calling die() during the flush. Let's just drop the return value altogether, as it only confuses callers into thinking that it might be useful. Only one call site actually checked the return value. We can drop that check, since it just led to a die() anyway. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-05pack-objects: name pack files after trailer hashLibravatar Jeff King1-7/+1
Our current scheme for naming packfiles is to calculate the sha1 hash of the sorted list of objects contained in the packfile. This gives us a unique name, so we are reasonably sure that two packs with the same name will contain the same objects. It does not, however, tell us that two such packs have the exact same bytes. This makes things awkward if we repack the same set of objects. Due to run-to-run variations, the bytes may not be identical (e.g., changed zlib or git versions, different source object reuse due to new packs in the repository, or even different deltas due to races during a multi-threaded delta search). In theory, this could be helpful to a program that cares that the packfile contains a certain set of objects, but does not care about the particular representation. In practice, no part of git makes use of that, and in many cases it is potentially harmful. For example, if a dumb http client fetches the .idx file, it must be sure to get the exact .pack that matches it. Similarly, a partial transfer of a .pack file cannot be safely resumed, as the actual bytes may have changed. This could also affect a local client which opened the .idx and .pack files, closes the .pack file (due to memory or file descriptor limits), and then re-opens a changed packfile. In all of these cases, git can detect the problem, as we have the sha1 of the bytes themselves in the pack trailer (which we verify on transfer), and the .idx file references the trailer from the matching packfile. But it would be simpler and more efficient to actually get the correct bytes, rather than noticing the problem and having to restart the operation. This patch simply uses the pack trailer sha1 as the pack name. It should be similarly unique, but covers the exact representation of the objects. Other parts of git should not care, as the pack name is returned by pack-objects and is essentially opaque. One test needs to be updated, because it actually corrupts a pack and expects that re-packing the corrupted bytes will use the same name. It won't anymore, but we can easily just use the name that pack-objects hands back. Signed-off-by: Jeff King <peff@peff.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-21Appease Sun Studio by renaming "tmpfile"Libravatar Ævar Arnfjörð Bjarmason1-3/+3
On Solaris the system headers define the "tmpfile" name, which'll cause Git compiled with Sun Studio 12 Update 1 to whine about us redefining the name: "pack-write.c", line 76: warning: name redefined by pragma redefine_extname declared static: tmpfile (E_PRAGMA_REDEFINE_STATIC) "sha1_file.c", line 2455: warning: name redefined by pragma redefine_extname declared static: tmpfile (E_PRAGMA_REDEFINE_STATIC) "fast-import.c", line 858: warning: name redefined by pragma redefine_extname declared static: tmpfile (E_PRAGMA_REDEFINE_STATIC) "builtin/index-pack.c", line 175: warning: name redefined by pragma redefine_extname declared static: tmpfile (E_PRAGMA_REDEFINE_STATIC) Just renaming the "tmpfile" variable to "tmp_file" in the relevant places is the easiest way to fix this. Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-12-16Merge branch 'jc/stream-to-pack'Libravatar Junio C Hamano1-0/+53
* jc/stream-to-pack: bulk-checkin: replace fast-import based implementation csum-file: introduce sha1file_checkpoint finish_tmp_packfile(): a helper function create_tmp_packfile(): a helper function write_pack_header(): a helper function Conflicts: pack.h
2011-11-16receive-pack, fetch-pack: reject bogus pack that records objects twiceLibravatar Junio C Hamano1-0/+4
When receive-pack & fetch-pack are run and store the pack obtained over the wire to a local repository, they internally run the index-pack command with the --strict option. Make sure that we reject incoming packfile that records objects twice to avoid spreading such a damage. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-10-28finish_tmp_packfile(): a helper functionLibravatar Junio C Hamano1-0/+31
Factor out a small logic out of the private write_pack_file() function in builtin/pack-objects.c. This changes the order of finishing multi-pack generation slightly. The code used to - adjust shared perm of temporary packfile - rename temporary packfile to the final name - update mtime of the packfile under the final name - adjust shared perm of temporary idxfile - rename temporary idxfile to the final name but because the helper does not want to do the mtime thing, the updated code does that step first and then all the rest. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-10-28create_tmp_packfile(): a helper functionLibravatar Junio C Hamano1-0/+10
Factor out a small logic out of the private write_pack_file() function in builtin/pack-objects.c Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-10-28write_pack_header(): a helper functionLibravatar Junio C Hamano1-0/+12
Factor out a small logic out of the private write_pack_file() function in builtin/pack-objects.c Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-27index-pack --verify: read anomalous offsets from v2 idx fileLibravatar Junio C Hamano1-1/+17
A pack v2 .idx file usually records offset using 64-bit representation only when the offset does not fit within 31-bit, but you can handcraft your .idx file to record smaller offset using 64-bit, storing all zero in the upper 4-byte. By inspecting the original idx file when running index-pack --verify, encode such low offsets that do not need to be in 64-bit but are encoded using 64-bit just like the original idx file so that we can still validate the pack/idx pair by comparing the idx file recomputed with the original. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-27write_idx_file: need_large_offset() helper functionLibravatar Junio C Hamano1-10/+19
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-27index-pack: --verifyLibravatar Junio C Hamano1-10/+16
Given an existing .pack file and the .idx file that describes it, this new mode of operation reads and re-index the packfile and makes sure the existing .idx file matches the result byte-for-byte. All the objects in the .pack file are validated during this operation as well. Unlike verify-pack, which visits each object described in the .idx file in the SHA-1 order, index-pack efficiently exploits the delta-chain to avoid rebuilding the objects that are used as the base of deltified objects over and over again while validating the objects, resulting in much quicker verification of the .pack file and its .idx file. This version however cannot verify a .pack/.idx pair with a handcrafted v2 index that uses 64-bit offset representation for offsets that would fit within 31-bit. You can create such an .idx file by giving a custom offset to --index-version option to the command. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2011-02-27write_idx_file: introduce a struct to hold idx customization optionsLibravatar Junio C Hamano1-6/+11
Remove two globals, pack_idx_default version and pack_idx_off32_limit, and place them in a pack_idx_option structure. Allow callers to pass it to write_idx_file() as a parameter. Adjust all callers to the API change. Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-02-23move encode_in_pack_object_header() to a better placeLibravatar Nicolas Pitre1-0/+27
Commit 1b22b6c897 made duplicated versions of encode_header() into a common version called encode_in_pack_object_header(). There is however a better location that sha1_file.c for such a function though, as sha1_file.c contains nothing related to the creation of packs, and it is quite populated already. Also the comment that was moved to the header file should really remain near the function as it covers implementation details and provides no information about the actual function interface. Signed-off-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2010-01-22make "index-pack" a built-inLibravatar Linus Torvalds1-2/+2
This required some fairly trivial packfile function 'const' cleanup, since the builtin commands get a const char *argv[] array. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-06-27Convert existing die(..., strerror(errno)) to die_errno()Libravatar Thomas Rast1-5/+5
Change calls to die(..., strerror(errno)) to use the new die_errno(). In the process, also make slight style adjustments: at least state _something_ about the function that failed (instead of just printing the pathname), and put paths in single quotes. Signed-off-by: Thomas Rast <trast@student.ethz.ch> Signed-off-by: Junio C Hamano <gitster@pobox.com>
2009-02-25Merge branch 'jc/maint-1.6.0-pack-directory'Libravatar Junio C Hamano1-4/+2
* jc/maint-1.6.0-pack-directory: Make sure objects/pack exists before creating a new pack
2009-02-25Make sure objects/pack exists before creating a new packLibravatar Junio C Hamano1-4/+2
In a repository created with git older than f49fb35 (git-init-db: create "pack" subdirectory under objects, 2005-06-27), objects/pack/ directory is not created upon initialization. It was Ok because subdirectories are created as needed inside directories init-db creates, and back then, packfiles were recent invention. After the said commit, new codepaths started relying on the presense of objects/pack/ directory in the repository. This was exacerbated with 8b4eb6b (Do not perform cross-directory renames when creating packs, 2008-09-22) that moved the location temporary pack files are created from objects/ directory to objects/pack/ directory, because moving temporary to the final location was done carefully with lazy leading directory creation. Many packfile related operations in such an old repository can fail mysteriously because of this. This commit introduces two helper functions to make things work better. - odb_mkstemp() is a specialized version of mkstemp() to refactor the code and teach it to create leading directories as needed; - odb_pack_keep() refactors the code to create a ".keep" file while create leading directories as needed. Signed-off-by: Junio C Hamano <gitster@pobox.com>