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94 Commits

Author SHA1 Message Date
Jeff King 1cf01a34ea consistently use "fallthrough" comments in switches
Gcc 7 adds -Wimplicit-fallthrough, which can warn when a
switch case falls through to the next case. The general idea
is that the compiler can't tell if this was intentional or
not, so you should annotate any intentional fall-throughs as
such, leaving it to complain about any unannotated ones.

There's a GNU __attribute__ which can be used for
annotation, but of course we'd have to #ifdef it away on
non-gcc compilers. Gcc will also recognize
specially-formatted comments, which matches our current
practice. Let's extend that practice to all of the
unannotated sites (which I did look over and verify that
they were behaving as intended).

Ideally in each case we'd actually give some reasons in the
comment about why we're falling through, or what we're
falling through to. And gcc does support that with
-Wimplicit-fallthrough=2, which relaxes the comment pattern
matching to anything that contains "fallthrough" (or a
variety of spelling variants). However, this isn't the
default for -Wimplicit-fallthrough, nor for -Wextra. In the
name of simplicity, it's probably better for us to support
the default level, which requires "fallthrough" to be the
only thing in the comment (modulo some window dressing like
"else" and some punctuation; see the gcc manual for the
complete set of patterns).

This patch suppresses all warnings due to
-Wimplicit-fallthrough. We might eventually want to add that
to the DEVELOPER Makefile knob, but we should probably wait
until gcc 7 is more widely adopted (since earlier versions
will complain about the unknown warning type).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-09-22 12:49:57 +09:00
Jonathan Tan 7709f468fd pack: move for_each_packed_object()
Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-08-23 15:12:07 -07:00
brian m. carlson 321c89bf5f sha1_name: convert GET_SHA1* flags to GET_OID*
Convert the flags for get_oid_with_context and friends to use "OID"
instead of "SHA1" in their names.

This transform was made by running the following one-liner on the
affected files:

  perl -pi -e 's/GET_SHA1/GET_OID/g'

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-17 13:54:51 -07:00
brian m. carlson e82caf384b sha1_name: convert get_sha1* to get_oid*
Now that all the callers of get_sha1 directly or indirectly use struct
object_id, rename the functions starting with get_sha1 to start with
get_oid.  Convert the internals in sha1_name.c to use struct object_id
as well, and eliminate explicit length checks where possible.  Convert a
use of 40 in get_oid_basic to GIT_SHA1_HEXSZ.

Outside of sha1_name.c and cache.h, this transition was made with the
following semantic patch:

@@
expression E1, E2;
@@
- get_sha1(E1, E2.hash)
+ get_oid(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1(E1, E2->hash)
+ get_oid(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_committish(E1, E2.hash)
+ get_oid_committish(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_committish(E1, E2->hash)
+ get_oid_committish(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_treeish(E1, E2.hash)
+ get_oid_treeish(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_treeish(E1, E2->hash)
+ get_oid_treeish(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_commit(E1, E2.hash)
+ get_oid_commit(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_commit(E1, E2->hash)
+ get_oid_commit(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_tree(E1, E2.hash)
+ get_oid_tree(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_tree(E1, E2->hash)
+ get_oid_tree(E1, E2)

@@
expression E1, E2;
@@
- get_sha1_blob(E1, E2.hash)
+ get_oid_blob(E1, &E2)

@@
expression E1, E2;
@@
- get_sha1_blob(E1, E2->hash)
+ get_oid_blob(E1, E2)

@@
expression E1, E2, E3, E4;
@@
- get_sha1_with_context(E1, E2, E3.hash, E4)
+ get_oid_with_context(E1, E2, &E3, E4)

@@
expression E1, E2, E3, E4;
@@
- get_sha1_with_context(E1, E2, E3->hash, E4)
+ get_oid_with_context(E1, E2, E3, E4)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-07-17 13:54:51 -07:00
Junio C Hamano 00b7cf2379 Merge branch 'jt/unify-object-info'
Code clean-ups.

* jt/unify-object-info:
  sha1_file: refactor has_sha1_file_with_flags
  sha1_file: do not access pack if unneeded
  sha1_file: teach sha1_object_info_extended more flags
  sha1_file: refactor read_object
  sha1_file: move delta base cache code up
  sha1_file: rename LOOKUP_REPLACE_OBJECT
  sha1_file: rename LOOKUP_UNKNOWN_OBJECT
  sha1_file: teach packed_object_info about typename
2017-07-05 13:32:57 -07:00
Junio C Hamano f31d23a399 Merge branch 'bw/config-h'
Fix configuration codepath to pay proper attention to commondir
that is used in multi-worktree situation, and isolate config API
into its own header file.

* bw/config-h:
  config: don't implicitly use gitdir or commondir
  config: respect commondir
  setup: teach discover_git_directory to respect the commondir
  config: don't include config.h by default
  config: remove git_config_iter
  config: create config.h
2017-06-24 14:28:41 -07:00
Jonathan Tan 1f0c0d36c1 sha1_file: rename LOOKUP_REPLACE_OBJECT
The LOOKUP_REPLACE_OBJECT flag controls whether the
lookup_replace_object() function is invoked by
sha1_object_info_extended(), read_sha1_file_extended(), and
lookup_replace_object_extended(), but it is not immediately clear which
functions accept that flag.

Therefore restrict this flag to only sha1_object_info_extended(),
renaming it appropriately to OBJECT_INFO_LOOKUP_REPLACE and adding some
documentation. Update read_sha1_file_extended() to have a boolean
parameter instead, and delete lookup_replace_object_extended().

parse_sha1_header() also passes this flag to
parse_sha1_header_extended() since commit 46f0344 ("sha1_file: support
reading from a loose object of unknown type", 2015-05-03), but that has
had no effect since that commit. Therefore this patch also removes this
flag from that invocation.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-21 18:54:43 -07:00
Jonathan Tan 19fc5e84a7 sha1_file: rename LOOKUP_UNKNOWN_OBJECT
The LOOKUP_UNKNOWN_OBJECT flag was introduced in commit 46f0344
("sha1_file: support reading from a loose object of unknown type",
2015-05-03) in order to support a feature in cat-file subsequently
introduced in commit 39e4ae3 ("cat-file: teach cat-file a
'--allow-unknown-type' option", 2015-05-03). Despite its name and
location in cache.h, this flag is used neither in
read_sha1_file_extended() nor in any of the lookup functions, but used
only in sha1_object_info_extended().

Therefore rename this flag to OBJECT_INFO_ALLOW_UNKNOWN_TYPE, taking the
name of the cat-file flag that invokes this feature, and move it closer
to the declaration of sha1_object_info_extended(). Also add
documentation for this flag.

OBJECT_INFO_ALLOW_UNKNOWN_TYPE is defined to 2, not 1, to avoid
conflicting with LOOKUP_REPLACE_OBJECT. Avoidance of this conflict is
necessary because sha1_object_info_extended() supports both flags.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-21 18:54:43 -07:00
Brandon Williams b2141fc1d2 config: don't include config.h by default
Stop including config.h by default in cache.h.  Instead only include
config.h in those files which require use of the config system.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-06-15 12:56:22 -07:00
Junio C Hamano 583c6a2295 Merge branch 'js/blame-lib'
The internal logic used in "git blame" has been libified to make it
easier to use by cgit.

* js/blame-lib: (29 commits)
  blame: move entry prepend to libgit
  blame: move scoreboard setup to libgit
  blame: move scoreboard-related methods to libgit
  blame: move fake-commit-related methods to libgit
  blame: move origin-related methods to libgit
  blame: move core structures to header
  blame: create entry prepend function
  blame: create scoreboard setup function
  blame: create scoreboard init function
  blame: rework methods that determine 'final' commit
  blame: wrap blame_sort and compare_blame_final
  blame: move progress updates to a scoreboard callback
  blame: make sanity_check use a callback in scoreboard
  blame: move no_whole_file_rename flag to scoreboard
  blame: move xdl_opts flags to scoreboard
  blame: move show_root flag to scoreboard
  blame: move reverse flag to scoreboard
  blame: move contents_from to scoreboard
  blame: move copy/move thresholds to scoreboard
  blame: move stat counters to scoreboard
  ...
2017-06-05 09:18:12 +09:00
Junio C Hamano 7ef0d04738 Merge branch 'jk/diff-blob'
The result from "git diff" that compares two blobs, e.g. "git diff
$commit1:$path $commit2:$path", used to be shown with the full
object name as given on the command line, but it is more natural to
use the $path in the output and use it to look up .gitattributes.

* jk/diff-blob:
  diff: use blob path for blob/file diffs
  diff: use pending "path" if it is available
  diff: use the word "path" instead of "name" for blobs
  diff: pass whole pending entry in blobinfo
  handle_revision_arg: record paths for pending objects
  handle_revision_arg: record modes for "a..b" endpoints
  t4063: add tests of direct blob diffs
  get_sha1_with_context: dynamically allocate oc->path
  get_sha1_with_context: always initialize oc->symlink_path
  sha1_name: consistently refer to object_context as "oc"
  handle_revision_arg: add handle_dotdot() helper
  handle_revision_arg: hoist ".." check out of range parsing
  handle_revision_arg: stop using "dotdot" as a generic pointer
  handle_revision_arg: simplify commit reference lookups
  handle_revision_arg: reset "dotdot" consistently
2017-06-02 15:06:05 +09:00
Jeff Smith 3a35cb2ea8 blame: move textconv_object with related functions
textconv_object is used in places other than blame.c and should be moved
to a more appropriate location.  Other textconv related functions are
located in diff.c so that seems as good a place as any.

Signed-off-by: Jeff Smith <whydoubt@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-24 15:41:50 +09:00
Jeff King dc944b65f1 get_sha1_with_context: dynamically allocate oc->path
When a sha1 lookup returns the tree path via "struct
object_context", it just copies it into a fixed-size buffer.
This means the result can be truncated, and it means our
"struct object_context" consumes a lot of stack space.

Instead, let's allocate a string on the heap. Because most
callers don't care about this information, we'll avoid doing
it by default (so they don't all have to start calling
free() on the result). There are basically two options for
the caller to signal to us that it's interested:

  1. By setting a pointer to storage in the object_context.

  2. By passing a flag in another parameter.

Doing (1) would match the way that sha1_object_info_extended()
works. But it would mean that every caller would have to
initialize the object_context, which they don't currently
have to do.

This patch does (2), and adds a new bit to the function's
flags field. All of the callers that look at the "path"
field are updated to pass the new flag.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-24 10:59:27 +09:00
Johannes Schindelin 05c2b7ba49 cat-file: fix memory leak
Discovered by Coverity.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-05-08 12:18:19 +09:00
brian m. carlson 910650d2f8 Rename sha1_array to oid_array
Since this structure handles an array of object IDs, rename it to struct
oid_array.  Also rename the accessor functions and the initialization
constant.

This commit was produced mechanically by providing non-Documentation
files to the following Perl one-liners:

    perl -pi -E 's/struct sha1_array/struct oid_array/g'
    perl -pi -E 's/\bsha1_array_/oid_array_/g'
    perl -pi -E 's/SHA1_ARRAY_INIT/OID_ARRAY_INIT/g'

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-31 08:33:56 -07:00
brian m. carlson 1b7ba794d2 Convert sha1_array_for_each_unique and for_each_abbrev to object_id
Make sha1_array_for_each_unique take a callback using struct object_id.
Since one of these callbacks is an argument to for_each_abbrev, convert
those as well.  Rename various functions, replacing "sha1" with "oid".

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-31 08:33:55 -07:00
brian m. carlson 98a72ddc12 Make sha1_array_append take a struct object_id *
Convert the callers to pass struct object_id by changing the function
declaration and definition and applying the following semantic patch:

@@
expression E1, E2;
@@
- sha1_array_append(E1, E2.hash)
+ sha1_array_append(E1, &E2)

@@
expression E1, E2;
@@
- sha1_array_append(E1, E2->hash)
+ sha1_array_append(E1, E2)

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-03-31 08:33:55 -07:00
brian m. carlson 76c1d9a096 Convert object iteration callbacks to struct object_id
Convert each_loose_object_fn and each_packed_object_fn to take a pointer
to struct object_id.  Update the various callbacks.  Convert several
40-based constants to use GIT_SHA1_HEXSZ.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2017-02-22 10:12:15 -08:00
Junio C Hamano e6e24c94df Merge branch 'jk/pack-objects-optim-mru'
"git pack-objects" in a repository with many packfiles used to
spend a lot of time looking for/at objects in them; the accesses to
the packfiles are now optimized by checking the most-recently-used
packfile first.

* jk/pack-objects-optim-mru:
  pack-objects: use mru list when iterating over packs
  pack-objects: break delta cycles before delta-search phase
  sha1_file: make packed_object_info public
  provide an initializer for "struct object_info"
2016-10-10 14:03:47 -07:00
Jeff King 16ddcd403b sha1_array: let callbacks interrupt iteration
The callbacks for iterating a sha1_array must have a void
return.  This is unlike our usual for_each semantics, where
a callback may interrupt iteration and have its value
propagated. Let's switch it to the usual form, which will
enable its use in more places (e.g., where we are replacing
an existing iteration with a different data structure).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-26 11:46:41 -07:00
Junio C Hamano 7889ed25ac Merge branch 'js/cat-file-filters'
Even though "git hash-objects", which is a tool to take an
on-filesystem data stream and put it into the Git object store,
allowed to perform the "outside-world-to-Git" conversions (e.g.
end-of-line conversions and application of the clean-filter), and
it had the feature on by default from very early days, its reverse
operation "git cat-file", which takes an object from the Git object
store and externalize for the consumption by the outside world,
lacked an equivalent mechanism to run the "Git-to-outside-world"
conversion.  The command learned the "--filters" option to do so.

* js/cat-file-filters:
  cat-file: support --textconv/--filters in batch mode
  cat-file --textconv/--filters: allow specifying the path separately
  cat-file: introduce the --filters option
  cat-file: fix a grammo in the man page
2016-09-21 15:15:19 -07:00
Junio C Hamano 4af9a7d344 Merge branch 'bc/object-id'
The "unsigned char sha1[20]" to "struct object_id" conversion
continues.  Notable changes in this round includes that ce->sha1,
i.e. the object name recorded in the cache_entry, turns into an
object_id.

It had merge conflicts with a few topics in flight (Christian's
"apply.c split", Dscho's "cat-file --filters" and Jeff Hostetler's
"status --porcelain-v2").  Extra sets of eyes double-checking for
mismerges are highly appreciated.

* bc/object-id:
  builtin/reset: convert to use struct object_id
  builtin/commit-tree: convert to struct object_id
  builtin/am: convert to struct object_id
  refs: add an update_ref_oid function.
  sha1_name: convert get_sha1_mb to struct object_id
  builtin/update-index: convert file to struct object_id
  notes: convert init_notes to use struct object_id
  builtin/rm: convert to use struct object_id
  builtin/blame: convert file to use struct object_id
  Convert read_mmblob to take struct object_id.
  notes-merge: convert struct notes_merge_pair to struct object_id
  builtin/checkout: convert some static functions to struct object_id
  streaming: make stream_blob_to_fd take struct object_id
  builtin: convert textconv_object to use struct object_id
  builtin/cat-file: convert some static functions to struct object_id
  builtin/cat-file: convert struct expand_data to use struct object_id
  builtin/log: convert some static functions to use struct object_id
  builtin/blame: convert struct origin to use struct object_id
  builtin/apply: convert static functions to struct object_id
  cache: convert struct cache_entry to use struct object_id
2016-09-19 13:47:19 -07:00
Johannes Schindelin 321459439e cat-file: support --textconv/--filters in batch mode
With this patch, --batch can be combined with --textconv or --filters.
For this to work, the input needs to have the form

	<object name><single white space><path>

so that the filters can be chosen appropriately.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-11 14:48:15 -07:00
Johannes Schindelin 7bcf341453 cat-file --textconv/--filters: allow specifying the path separately
There are circumstances when it is relatively easy to figure out the
object name for a given path, but not the name of the containing tree.
For example, when looking at a diff generated by Git, the object names
are recorded, but not the revision. As a matter of fact, the revisions
from which the diff was generated may not even exist locally.

In such a case, the user would have to generate a fake revision just to
be able to use --textconv or --filters.

Let's simplify this dramatically, because we do not really need that
revision at all: all we care about is that we know the path. In the
scenario described above, we do know the path, and we just want to
specify it separately from the object name.

Example usage:

	git cat-file --textconv --path=main.c 0f1937fd

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-11 14:48:15 -07:00
Johannes Schindelin b9e62f6011 cat-file: introduce the --filters option
The --filters option applies the convert_to_working_tree() filter for
the path when showing the contents of a regular file blob object;
the contents are written out as-is for other types of objects.

This feature comes in handy when a 3rd-party tool wants to work with
the contents of files from past revisions as if they had been checked
out, but without detouring via temporary files.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-11 14:47:46 -07:00
Alex Henrie 88c782942c cat-file: put spaces around pipes in usage string
This makes the style a little more consistent with other usage strings,
and will resolve a warning at
https://www.softcatala.org/recursos/quality/git.html

Signed-off-by: Alex Henrie <alexhenrie24@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-08 12:16:38 -07:00
brian m. carlson 7eda0e4fbb streaming: make stream_blob_to_fd take struct object_id
Since all of its callers have been updated, modify stream_blob_to_fd to
take a struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson acad70d106 builtin: convert textconv_object to use struct object_id
Since all of its callers have been updated, make textconv_object take a
struct object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson 63ecb99e0d builtin/cat-file: convert some static functions to struct object_id
Convert all of the static functions that are not callbacks to use struct
object_id.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
brian m. carlson cd4f77beb7 builtin/cat-file: convert struct expand_data to use struct object_id
Convert struct cache_entry to use struct object_id by applying the
following semantic patch and the object_id transforms from contrib,
plus the actual change to the struct:

@@
struct expand_data E1;
@@
- E1.sha1
+ E1.oid.hash

@@
struct expand_data *E1;
@@
- E1->sha1
+ E1->oid.hash

@@
struct expand_data E1;
@@
- E1.delta_base_sha1
+ E1.delta_base_oid.hash

@@
struct expand_data *E1;
@@
- E1->delta_base_sha1
+ E1->delta_base_oid.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-09-07 12:59:42 -07:00
Jeff King 27b5c1a065 provide an initializer for "struct object_info"
An all-zero initializer is fine for this struct, but because
the first element is a pointer, call sites need to know to
use "NULL" instead of "0". Otherwise some static checkers
like "sparse" will complain; see d099b71 (Fix some sparse
warnings, 2013-07-18) for example.  So let's provide an
initializer to make this easier to get right.

But let's also comment that memset() to zero is explicitly
OK[1]. One of the callers embeds object_info in another
struct which is initialized via memset (expand_data in
builtin/cat-file.c). Since our subset of C doesn't allow
assignment from a compound literal, handling this in any
other way is awkward, so we'd like to keep the ability to
initialize by memset(). By documenting this property, it
should make anybody who wants to change the initializer
think twice before doing so.

There's one other caller of interest. In parse_sha1_header(),
we did not initialize the struct fully in the first place.
This turned out not to be a bug because the sub-function it
calls does not look at any other fields except the ones we
did initialize. But that assumption might not hold in the
future, so it's a dangerous construct. This patch switches
it to initializing the whole struct, which protects us
against unexpected reads of the other fields.

[1] Obviously using memset() to initialize a pointer
    violates the C standard, but we long ago decided that it
    was an acceptable tradeoff in the real world.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-08-11 10:42:23 -07:00
Junio C Hamano ad2d777604 Merge branch 'nd/pack-ofs-4gb-limit'
"git pack-objects" and "git index-pack" mostly operate with off_t
when talking about the offset of objects in a packfile, but there
were a handful of places that used "unsigned long" to hold that
value, leading to an unintended truncation.

* nd/pack-ofs-4gb-limit:
  fsck: use streaming interface for large blobs in pack
  pack-objects: do not truncate result in-pack object size on 32-bit systems
  index-pack: correct "offset" type in unpack_entry_data()
  index-pack: report correct bad object offsets even if they are large
  index-pack: correct "len" type in unpack_data()
  sha1_file.c: use type off_t* for object_info->disk_sizep
  pack-objects: pass length to check_pack_crc() without truncation
2016-07-28 10:34:42 -07:00
Nguyễn Thái Ngọc Duy 166df26f28 sha1_file.c: use type off_t* for object_info->disk_sizep
This field, filled by sha1_object_info() contains the on-disk size of
an object, which could go over 4GB limit of unsigned long on 32-bit
systems. Use off_t for it instead and update all callers.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-07-13 09:14:20 -07:00
Junio C Hamano 628991391d Merge branch 'jk/cat-file-buffered-batch-all'
"git cat-file --batch-all" has been sped up, by taking advantage
of the fact that it does not have to read a list of objects, in two
ways.

* jk/cat-file-buffered-batch-all:
  cat-file: default to --buffer when --batch-all-objects is used
  cat-file: avoid noop calls to sha1_object_info_extended
2016-05-31 12:40:54 -07:00
Jeff King 6a36e1e7bb cat-file: default to --buffer when --batch-all-objects is used
Traditionally cat-file's batch-mode does not do any output
buffering. The reason is that a caller may have pipes
connected to its input and output, and would want to use
cat-file interactively, getting output immediately for each
input it sends.

This may involve a lot of small write() calls, which can be
slow. So we introduced --buffer to improve this, but we
can't turn it on by default, as it would break the
interactive case above.

However, when --batch-all-objects is used, we do not read
stdin at all. We generate the output ourselves as quickly as
possible, and then exit. In this case buffering is a strict
win, and it is simply a hassle for the user to have to
remember to specify --buffer.

This patch makes --buffer the default when --batch-all-objects
is used. Specifying "--buffer" manually is still OK, and you
can even override it with "--no-buffer" if you're a
masochist (or debugging).

For some real numbers, running:

  git cat-file --batch-all-objects --batch-check='%(objectname)'

on torvalds/linux goes from:

  real    0m1.464s
  user    0m1.208s
  sys     0m0.252s

to:

  real    0m1.230s
  user    0m1.172s
  sys     0m0.056s

for a 16% speedup.

Suggested-by: Charles Bailey <charles@hashpling.org>
Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-18 14:17:39 -07:00
Jeff King 845de33a5b cat-file: avoid noop calls to sha1_object_info_extended
It is not unreasonable to ask cat-file for a batch-check
format of simply "%(objectname)". At first glance this seems
like a noop (you are generally already feeding the object
names on stdin!), but it has a few uses:

  1. With --batch-all-objects, you can generate a listing of
     the sha1s present in the repository, without any input.

  2. You do not have to feed sha1s; you can feed arbitrary
     sha1 expressions and have git resolve them en masse.

  3. You can even feed a raw sha1, with the result that git
     will tell you whether we actually have the object or
     not.

In case 3, the call to sha1_object_info is useful; it tells
us whether the object exists or not (technically we could
swap this out for has_sha1_file, but the cost is roughly the
same).

In case 2, the existence check is of debatable value. A
mass-resolution might prefer performance to safety (against
outputting a value for a corrupted ref, for example).
However, the object lookup cost is likely not as noticeable
compared to the resolution cost. And since we have provided
that safety in the past, the conservative choice is to keep
it.

In case 1, though, the object lookup is a definite noop; we
know about the object because we found it in the object
database. There is no new information gained by making the
call.

This patch detects that case and optimizes out the call.
Here are best-of-five timings for linux.git:

  [before]
  $ time git cat-file --buffer \
                      --batch-all-objects \
                      --batch-check='%(objectname)'
  real    0m2.117s
  user    0m2.044s
  sys     0m0.072s

  [after]
  $ time git cat-file --buffer \
                      --batch-all-objects \
                      --batch-check='%(objectname)'
  real    0m1.230s
  user    0m1.176s
  sys     0m0.052s

There are two implementation details to note here.

One is that we detect the noop case by seeing that "struct
object_info" does not request any information. But besides
object existence, there is one other piece of information
which sha1_object_info may fill in: whether the object is
cached, loose, or packed. We don't currently provide that
information in the output, but if we were to do so later,
we'd need to take note and disable the optimization in that
case.

And that leads to the second note. If we were to output
that information, a better implementation would be to
remember where we saw the object in --batch-all-objects in
the first place, and avoid looking it up again by sha1.

In fact, we could probably squeeze out some extra
performance for less-trivial cases, too, by remembering the
pack location where we saw the object, and going directly
there to find its information (like type, size, etc). That
would in theory make this optimization unnecessary.

I didn't pursue that path here for two reasons:

  1. It's non-trivial to implement, and has memory
     implications. Because we sort and de-dup the list of
     output sha1s, we'd have to record the pack information
     for each object, too.

  2. It doesn't save as much as you might hope. It saves the
     find_pack_entry() call, but getting the size and type
     for deltified objects requires walking down the delta
     chain (for the real type) or reading the delta data
     header (for the size). These costs tend to dominate the
     non-trivial cases.

By contrast, this optimization is easy and self-contained,
and speeds up a real-world case I've used.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-05-18 14:17:38 -07:00
Junio C Hamano b42ca3dd0f cat-file: read batch stream with strbuf_getline()
It is possible to prepare a text file with a DOS editor and feed it
as a batch command stream to the command.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15 10:35:06 -08:00
Junio C Hamano 8f309aeb82 strbuf: introduce strbuf_getline_{lf,nul}()
The strbuf_getline() interface allows a byte other than LF or NUL as
the line terminator, but this is only because I wrote these
codepaths anticipating that there might be a value other than NUL
and LF that could be useful when I introduced line_termination long
time ago.  No useful caller that uses other value has emerged.

By now, it is clear that the interface is overly broad without a
good reason.  Many codepaths have hardcoded preference to read
either LF terminated or NUL terminated records from their input, and
then call strbuf_getline() with LF or NUL as the third parameter.

This step introduces two thin wrappers around strbuf_getline(),
namely, strbuf_getline_lf() and strbuf_getline_nul(), and
mechanically rewrites these call sites to call either one of
them.  The changes contained in this patch are:

 * introduction of these two functions in strbuf.[ch]

 * mechanical conversion of all callers to strbuf_getline() with
   either '\n' or '\0' as the third parameter to instead call the
   respective thin wrapper.

After this step, output from "git grep 'strbuf_getline('" would
become a lot smaller.  An interim goal of this series is to make
this an empty set, so that we can have strbuf_getline_crlf() take
over the shorter name strbuf_getline().

Signed-off-by: Junio C Hamano <gitster@pobox.com>
2016-01-15 10:12:51 -08:00
Junio C Hamano 33e8fc8740 usage: do not insist that standard input must come from a file
The synopsys text and the usage string of subcommands that read list
of things from the standard input are often shown like this:

	git gostak [--distim] < <list-of-doshes>

This is problematic in a number of ways:

 * The way to use these commands is more often to feed them the
   output from another command, not feed them from a file.

 * Manual pages outside Git, commands that operate on the data read
   from the standard input, e.g "sort", "grep", "sed", etc., are not
   described with such a "< redirection-from-file" in their synopsys
   text.  Our doing so introduces inconsistency.

 * We do not insist on where the output should go, by saying

	git gostak [--distim] < <list-of-doshes> > <output>

 * As it is our convention to enclose placeholders inside <braket>,
   the redirection operator followed by a placeholder filename
   becomes very hard to read, both in the documentation and in the
   help text.

Let's clean them all up, after making sure that the documentation
clearly describes the modes that take information from the standard
input and what kind of things are expected on the input.

[jc: stole example for fmt-merge-msg from Jonathan]

Helped-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-10-16 15:27:52 -07:00
Jeff King 3115ee45c8 cat-file: sort and de-dup output of --batch-all-objects
The sorting we could probably live without, but printing
duplicates is just a hassle for the user, who must then
de-dup themselves (or risk a wrong answer if they are doing
something like counting objects with a particular property).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-26 09:24:42 -07:00
Jeff King 6a951937ae cat-file: add --batch-all-objects option
It can sometimes be useful to examine all objects in the
repository. Normally this is done with "git rev-list --all
--objects", but:

  1. That shows only reachable objects. You may want to look
     at all available objects.

  2. It's slow. We actually open each object to walk the
     graph. If your operation is OK with seeing unreachable
     objects, it's an order of magnitude faster to just
     enumerate the loose directories and pack indices.

You can do this yourself using "ls" and "git show-index",
but it's non-obvious.  This patch adds an option to
"cat-file --batch-check" to operate on all available
objects (rather than reading names from stdin).

This is based on a proposal by Charles Bailey to provide a
separate "git list-all-objects" command. That is more
orthogonal, as it splits enumerating the objects from
getting information about them. However, in practice you
will either:

  a. Feed the list of objects directly into cat-file anyway,
     so you can find out information about them. Keeping it
     in a single process is more efficient.

  b. Ask the listing process to start telling you more
     information about the objects, in which case you will
     reinvent cat-file's batch-check formatter.

Adding a cat-file option is simple and efficient. And if you
really do want just the object names, you can always do:

  git cat-file --batch-check='%(objectname)' --batch-all-objects

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:55:52 -07:00
Jeff King 44b877e9bc cat-file: split batch_one_object into two stages
There are really two things going on in this function:

  1. We convert the name we got on stdin to a sha1.

  2. We look up and print information on the sha1.

Let's split out the second half so that we can call it
separately.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:55:52 -07:00
Jeff King 82330950d9 cat-file: stop returning value from batch_one_object
If batch_one_object returns an error code, we stop reading
input.  However, it will only do so if we feed it NULL,
which cannot happen; we give it the "buf" member of a
strbuf, which is always non-NULL.

We did originally stop on other errors (like a missing
object), but this was changed in 3c076db (cat-file --batch /
--batch-check: do not exit if hashes are missing,
2008-06-09). These days we keep going for any per-object
error (and print "missing" when necessary).

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:55:52 -07:00
Jeff King fc4937c372 cat-file: add --buffer option
We use a direct write() to output the results of --batch and
--batch-check. This is good for processes feeding the input
and reading the output interactively, but it introduces
measurable overhead if you do not want this feature. For
example, on linux.git:

  $ git rev-list --objects --all | cut -d' ' -f1 >objects
  $ time git cat-file --batch-check='%(objectsize)' \
          <objects >/dev/null
  real    0m5.440s
  user    0m5.060s
  sys     0m0.384s

This patch adds an option to use regular stdio buffering:

  $ time git cat-file --batch-check='%(objectsize)' \
          --buffer <objects >/dev/null
  real    0m4.975s
  user    0m4.888s
  sys     0m0.092s

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:55:52 -07:00
Jeff King bfd155943e cat-file: move batch_options definition to top of file
That way all of the functions can make use of it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:55:52 -07:00
Jeff King ad42f28d0c cat-file: minor style fix in options list
We do not put extra whitespace before the first macro
argument.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-06-22 14:55:52 -07:00
Junio C Hamano 67f0b6f3b2 Merge branch 'dt/cat-file-follow-symlinks'
"git cat-file --batch(-check)" learned the "--follow-symlinks"
option that follows an in-tree symbolic link when asked about an
object via extended SHA-1 syntax, e.g. HEAD:RelNotes that points at
Documentation/RelNotes/2.5.0.txt.  With the new option, the command
behaves as if HEAD:Documentation/RelNotes/2.5.0.txt was given as
input instead.

* dt/cat-file-follow-symlinks:
  cat-file: add --follow-symlinks to --batch
  sha1_name: get_sha1_with_context learns to follow symlinks
  tree-walk: learn get_tree_entry_follow_symlinks
2015-06-01 12:45:16 -07:00
David Turner 122d53464b cat-file: add --follow-symlinks to --batch
This wires the in-repo-symlink following code through to the cat-file
builtin.  In the event of an out-of-repo link, cat-file will print
the link in a new format.

Signed-off-by: David Turner <dturner@twopensource.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-20 13:46:21 -07:00
Karthik Nayak 39e4ae3880 cat-file: teach cat-file a '--allow-unknown-type' option
'git cat-file' throws an error while trying to print the type or
size of a broken/corrupt object. This is because these objects are
usually of unknown types.

Teach git cat-file a '--allow-unknown-type' option where it prints
the type or size of a broken/corrupt object without throwing
an error.

Modify '-t' and '-s' options to call sha1_object_info_extended()
directly to support the '--allow-unknown-type' option.

Add documentation for 'cat-file --allow-unknown-type'.

Helped-by: Junio C Hamano <gitster@pobox.com>
Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>

cat-file: add documentation for '--allow-unknown-type' option.

Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-06 13:35:48 -07:00
Karthik Nayak b48158ac94 cat-file: make the options mutually exclusive
We only parse the options if 2 or 3 arguments are specified.
Update 'struct option options[]' to use OPT_CMDMODE rather than
OPT_SET_INT to allow only one mutually exclusive option and avoid the
need for checking number of arguments. This was written by Junio C Hamano,
tested by me.

Helped-by: Junio C Hamano <gitster@pobox.com>
Signed-off-by: Karthik Nayak <karthik.188@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2015-05-06 13:35:48 -07:00