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Copy pathdiff_tform.c
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660 lines (522 loc) · 17.1 KB
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/*
* Copyright (C) the libgit2 contributors. All rights reserved.
*
* This file is part of libgit2, distributed under the GNU GPL v2 with
* a Linking Exception. For full terms see the included COPYING file.
*/
#include "common.h"
#include "diff.h"
#include "git2/config.h"
#include "git2/blob.h"
#include "hashsig.h"
static git_diff_delta *diff_delta__dup(
const git_diff_delta *d, git_pool *pool)
{
git_diff_delta *delta = git__malloc(sizeof(git_diff_delta));
if (!delta)
return NULL;
memcpy(delta, d, sizeof(git_diff_delta));
delta->old_file.path = git_pool_strdup(pool, d->old_file.path);
if (delta->old_file.path == NULL)
goto fail;
if (d->new_file.path != d->old_file.path) {
delta->new_file.path = git_pool_strdup(pool, d->new_file.path);
if (delta->new_file.path == NULL)
goto fail;
} else {
delta->new_file.path = delta->old_file.path;
}
return delta;
fail:
git__free(delta);
return NULL;
}
static git_diff_delta *diff_delta__merge_like_cgit(
const git_diff_delta *a, const git_diff_delta *b, git_pool *pool)
{
git_diff_delta *dup;
/* Emulate C git for merging two diffs (a la 'git diff <sha>').
*
* When C git does a diff between the work dir and a tree, it actually
* diffs with the index but uses the workdir contents. This emulates
* those choices so we can emulate the type of diff.
*
* We have three file descriptions here, let's call them:
* f1 = a->old_file
* f2 = a->new_file AND b->old_file
* f3 = b->new_file
*/
/* if f2 == f3 or f2 is deleted, then just dup the 'a' diff */
if (b->status == GIT_DELTA_UNMODIFIED || a->status == GIT_DELTA_DELETED)
return diff_delta__dup(a, pool);
/* otherwise, base this diff on the 'b' diff */
if ((dup = diff_delta__dup(b, pool)) == NULL)
return NULL;
/* If 'a' status is uninteresting, then we're done */
if (a->status == GIT_DELTA_UNMODIFIED)
return dup;
assert(a->status != GIT_DELTA_UNMODIFIED);
assert(b->status != GIT_DELTA_UNMODIFIED);
/* A cgit exception is that the diff of a file that is only in the
* index (i.e. not in HEAD nor workdir) is given as empty.
*/
if (dup->status == GIT_DELTA_DELETED) {
if (a->status == GIT_DELTA_ADDED)
dup->status = GIT_DELTA_UNMODIFIED;
/* else don't overwrite DELETE status */
} else {
dup->status = a->status;
}
git_oid_cpy(&dup->old_file.oid, &a->old_file.oid);
dup->old_file.mode = a->old_file.mode;
dup->old_file.size = a->old_file.size;
dup->old_file.flags = a->old_file.flags;
return dup;
}
int git_diff_merge(
git_diff_list *onto,
const git_diff_list *from)
{
int error = 0;
git_pool onto_pool;
git_vector onto_new;
git_diff_delta *delta;
bool ignore_case = false;
unsigned int i, j;
assert(onto && from);
if (!from->deltas.length)
return 0;
if (git_vector_init(
&onto_new, onto->deltas.length, git_diff_delta__cmp) < 0 ||
git_pool_init(&onto_pool, 1, 0) < 0)
return -1;
if ((onto->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0 ||
(from->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0)
{
ignore_case = true;
/* This function currently only supports merging diff lists that
* are sorted identically. */
assert((onto->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0 &&
(from->opts.flags & GIT_DIFF_DELTAS_ARE_ICASE) != 0);
}
for (i = 0, j = 0; i < onto->deltas.length || j < from->deltas.length; ) {
git_diff_delta *o = GIT_VECTOR_GET(&onto->deltas, i);
const git_diff_delta *f = GIT_VECTOR_GET(&from->deltas, j);
int cmp = !f ? -1 : !o ? 1 : STRCMP_CASESELECT(ignore_case, o->old_file.path, f->old_file.path);
if (cmp < 0) {
delta = diff_delta__dup(o, &onto_pool);
i++;
} else if (cmp > 0) {
delta = diff_delta__dup(f, &onto_pool);
j++;
} else {
delta = diff_delta__merge_like_cgit(o, f, &onto_pool);
i++;
j++;
}
/* the ignore rules for the target may not match the source
* or the result of a merged delta could be skippable...
*/
if (git_diff_delta__should_skip(&onto->opts, delta)) {
git__free(delta);
continue;
}
if ((error = !delta ? -1 : git_vector_insert(&onto_new, delta)) < 0)
break;
}
if (!error) {
git_vector_swap(&onto->deltas, &onto_new);
git_pool_swap(&onto->pool, &onto_pool);
onto->new_src = from->new_src;
/* prefix strings also come from old pool, so recreate those.*/
onto->opts.old_prefix =
git_pool_strdup_safe(&onto->pool, onto->opts.old_prefix);
onto->opts.new_prefix =
git_pool_strdup_safe(&onto->pool, onto->opts.new_prefix);
}
git_vector_foreach(&onto_new, i, delta)
git__free(delta);
git_vector_free(&onto_new);
git_pool_clear(&onto_pool);
return error;
}
static int find_similar__hashsig_for_file(
void **out, const git_diff_file *f, const char *path, void *p)
{
git_hashsig_option_t opt = (git_hashsig_option_t)p;
GIT_UNUSED(f);
return git_hashsig_create_fromfile((git_hashsig **)out, path, opt);
}
static int find_similar__hashsig_for_buf(
void **out, const git_diff_file *f, const char *buf, size_t len, void *p)
{
git_hashsig_option_t opt = (git_hashsig_option_t)p;
GIT_UNUSED(f);
return git_hashsig_create((git_hashsig **)out, buf, len, opt);
}
static void find_similar__hashsig_free(void *sig, void *payload)
{
GIT_UNUSED(payload);
git_hashsig_free(sig);
}
static int find_similar__calc_similarity(
int *score, void *siga, void *sigb, void *payload)
{
GIT_UNUSED(payload);
*score = git_hashsig_compare(siga, sigb);
return 0;
}
#define DEFAULT_THRESHOLD 50
#define DEFAULT_BREAK_REWRITE_THRESHOLD 60
#define DEFAULT_TARGET_LIMIT 200
static int normalize_find_opts(
git_diff_list *diff,
git_diff_find_options *opts,
git_diff_find_options *given)
{
git_config *cfg = NULL;
if (diff->repo != NULL &&
git_repository_config__weakptr(&cfg, diff->repo) < 0)
return -1;
if (given != NULL)
memcpy(opts, given, sizeof(*opts));
else {
const char *val = NULL;
GIT_INIT_STRUCTURE(opts, GIT_DIFF_FIND_OPTIONS_VERSION);
opts->flags = GIT_DIFF_FIND_RENAMES;
if (git_config_get_string(&val, cfg, "diff.renames") < 0)
giterr_clear();
else if (val &&
(!strcasecmp(val, "copies") || !strcasecmp(val, "copy")))
opts->flags = GIT_DIFF_FIND_RENAMES | GIT_DIFF_FIND_COPIES;
}
GITERR_CHECK_VERSION(opts, GIT_DIFF_FIND_OPTIONS_VERSION, "git_diff_find_options");
/* some flags imply others */
if (opts->flags & GIT_DIFF_FIND_RENAMES_FROM_REWRITES)
opts->flags |= GIT_DIFF_FIND_RENAMES;
if (opts->flags & GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED)
opts->flags |= GIT_DIFF_FIND_COPIES;
#define USE_DEFAULT(X) ((X) == 0 || (X) > 100)
if (USE_DEFAULT(opts->rename_threshold))
opts->rename_threshold = DEFAULT_THRESHOLD;
if (USE_DEFAULT(opts->rename_from_rewrite_threshold))
opts->rename_from_rewrite_threshold = DEFAULT_THRESHOLD;
if (USE_DEFAULT(opts->copy_threshold))
opts->copy_threshold = DEFAULT_THRESHOLD;
if (USE_DEFAULT(opts->break_rewrite_threshold))
opts->break_rewrite_threshold = DEFAULT_BREAK_REWRITE_THRESHOLD;
#undef USE_DEFAULT
if (!opts->target_limit) {
int32_t limit = 0;
opts->target_limit = DEFAULT_TARGET_LIMIT;
if (git_config_get_int32(&limit, cfg, "diff.renameLimit") < 0)
giterr_clear();
else if (limit > 0)
opts->target_limit = limit;
}
/* assign the internal metric with whitespace flag as payload */
if (!opts->metric) {
opts->metric = git__malloc(sizeof(git_diff_similarity_metric));
GITERR_CHECK_ALLOC(opts->metric);
opts->metric->file_signature = find_similar__hashsig_for_file;
opts->metric->buffer_signature = find_similar__hashsig_for_buf;
opts->metric->free_signature = find_similar__hashsig_free;
opts->metric->similarity = find_similar__calc_similarity;
if (opts->flags & GIT_DIFF_FIND_IGNORE_WHITESPACE)
opts->metric->payload = (void *)GIT_HASHSIG_IGNORE_WHITESPACE;
else if (opts->flags & GIT_DIFF_FIND_DONT_IGNORE_WHITESPACE)
opts->metric->payload = (void *)GIT_HASHSIG_NORMAL;
else
opts->metric->payload = (void *)GIT_HASHSIG_SMART_WHITESPACE;
}
return 0;
}
static int apply_splits_and_deletes(git_diff_list *diff, size_t expected_size)
{
git_vector onto = GIT_VECTOR_INIT;
size_t i;
git_diff_delta *delta;
if (git_vector_init(&onto, expected_size, git_diff_delta__cmp) < 0)
return -1;
/* build new delta list without TO_DELETE and splitting TO_SPLIT */
git_vector_foreach(&diff->deltas, i, delta) {
if ((delta->flags & GIT_DIFF_FLAG__TO_DELETE) != 0)
continue;
if ((delta->flags & GIT_DIFF_FLAG__TO_SPLIT) != 0) {
git_diff_delta *deleted = diff_delta__dup(delta, &diff->pool);
if (!deleted)
goto on_error;
deleted->status = GIT_DELTA_DELETED;
memset(&deleted->new_file, 0, sizeof(deleted->new_file));
deleted->new_file.path = deleted->old_file.path;
deleted->new_file.flags |= GIT_DIFF_FLAG_VALID_OID;
if (git_vector_insert(&onto, deleted) < 0)
goto on_error;
delta->status = GIT_DELTA_ADDED;
memset(&delta->old_file, 0, sizeof(delta->old_file));
delta->old_file.path = delta->new_file.path;
delta->old_file.flags |= GIT_DIFF_FLAG_VALID_OID;
}
if (git_vector_insert(&onto, delta) < 0)
goto on_error;
}
/* cannot return an error past this point */
git_vector_foreach(&diff->deltas, i, delta)
if ((delta->flags & GIT_DIFF_FLAG__TO_DELETE) != 0)
git__free(delta);
/* swap new delta list into place */
git_vector_sort(&onto);
git_vector_swap(&diff->deltas, &onto);
git_vector_free(&onto);
return 0;
on_error:
git_vector_foreach(&onto, i, delta)
git__free(delta);
git_vector_free(&onto);
return -1;
}
GIT_INLINE(git_diff_file *) similarity_get_file(git_diff_list *diff, size_t idx)
{
git_diff_delta *delta = git_vector_get(&diff->deltas, idx / 2);
return (idx & 1) ? &delta->new_file : &delta->old_file;
}
static int similarity_calc(
git_diff_list *diff,
git_diff_find_options *opts,
size_t file_idx,
void **cache)
{
int error = 0;
git_diff_file *file = similarity_get_file(diff, file_idx);
git_iterator_type_t src = (file_idx & 1) ? diff->old_src : diff->new_src;
if (src == GIT_ITERATOR_TYPE_WORKDIR) { /* compute hashsig from file */
git_buf path = GIT_BUF_INIT;
/* TODO: apply wd-to-odb filters to file data if necessary */
if (!(error = git_buf_joinpath(
&path, git_repository_workdir(diff->repo), file->path)))
error = opts->metric->file_signature(
&cache[file_idx], file, path.ptr, opts->metric->payload);
git_buf_free(&path);
} else { /* compute hashsig from blob buffer */
git_blob *blob = NULL;
/* TODO: add max size threshold a la diff? */
if ((error = git_blob_lookup(&blob, diff->repo, &file->oid)) < 0)
return error;
error = opts->metric->buffer_signature(
&cache[file_idx], file, git_blob_rawcontent(blob),
git_blob_rawsize(blob), opts->metric->payload);
git_blob_free(blob);
}
return error;
}
static int similarity_measure(
git_diff_list *diff,
git_diff_find_options *opts,
void **cache,
size_t a_idx,
size_t b_idx)
{
int score = 0;
git_diff_file *a_file = similarity_get_file(diff, a_idx);
git_diff_file *b_file = similarity_get_file(diff, b_idx);
if (GIT_MODE_TYPE(a_file->mode) != GIT_MODE_TYPE(b_file->mode))
return 0;
if (git_oid_cmp(&a_file->oid, &b_file->oid) == 0)
return 100;
/* update signature cache if needed */
if (!cache[a_idx] && similarity_calc(diff, opts, a_idx, cache) < 0)
return -1;
if (!cache[b_idx] && similarity_calc(diff, opts, b_idx, cache) < 0)
return -1;
/* compare signatures */
if (opts->metric->similarity(
&score, cache[a_idx], cache[b_idx], opts->metric->payload) < 0)
return -1;
/* clip score */
if (score < 0)
score = 0;
else if (score > 100)
score = 100;
return score;
}
#define FLAG_SET(opts,flag_name) ((opts.flags & flag_name) != 0)
int git_diff_find_similar(
git_diff_list *diff,
git_diff_find_options *given_opts)
{
size_t i, j, cache_size, *matches;
int error = 0, similarity;
git_diff_delta *from, *to;
git_diff_find_options opts;
size_t tried_targets, num_rewrites = 0;
void **cache;
if ((error = normalize_find_opts(diff, &opts, given_opts)) < 0)
return error;
/* TODO: maybe abort if deltas.length > target_limit ??? */
cache_size = diff->deltas.length * 2; /* must store b/c length may change */
cache = git__calloc(cache_size, sizeof(void *));
GITERR_CHECK_ALLOC(cache);
matches = git__calloc(diff->deltas.length, sizeof(size_t));
GITERR_CHECK_ALLOC(matches);
/* first break MODIFIED records that are too different (if requested) */
if (FLAG_SET(opts, GIT_DIFF_FIND_AND_BREAK_REWRITES)) {
git_vector_foreach(&diff->deltas, i, from) {
if (from->status != GIT_DELTA_MODIFIED)
continue;
similarity = similarity_measure(
diff, &opts, cache, 2 * i, 2 * i + 1);
if (similarity < 0) {
error = similarity;
goto cleanup;
}
if ((unsigned int)similarity < opts.break_rewrite_threshold) {
from->flags |= GIT_DIFF_FLAG__TO_SPLIT;
num_rewrites++;
}
}
}
/* next find the most similar delta for each rename / copy candidate */
git_vector_foreach(&diff->deltas, i, from) {
tried_targets = 0;
/* skip things that aren't blobs */
if (GIT_MODE_TYPE(from->old_file.mode) !=
GIT_MODE_TYPE(GIT_FILEMODE_BLOB))
continue;
/* don't check UNMODIFIED files as source unless given option */
if (from->status == GIT_DELTA_UNMODIFIED &&
!FLAG_SET(opts, GIT_DIFF_FIND_COPIES_FROM_UNMODIFIED))
continue;
/* skip all but DELETED files unless copy detection is on */
if (!FLAG_SET(opts, GIT_DIFF_FIND_COPIES) &&
from->status != GIT_DELTA_DELETED &&
(from->flags & GIT_DIFF_FLAG__TO_SPLIT) == 0)
continue;
git_vector_foreach(&diff->deltas, j, to) {
if (i == j)
continue;
/* skip things that aren't blobs */
if (GIT_MODE_TYPE(to->new_file.mode) !=
GIT_MODE_TYPE(GIT_FILEMODE_BLOB))
continue;
switch (to->status) {
case GIT_DELTA_ADDED:
case GIT_DELTA_UNTRACKED:
case GIT_DELTA_RENAMED:
case GIT_DELTA_COPIED:
break;
case GIT_DELTA_MODIFIED:
if ((to->flags & GIT_DIFF_FLAG__TO_SPLIT) == 0)
continue;
break;
default:
/* only the above status values should be checked */
continue;
}
/* cap on maximum files we'll examine (per "from" file) */
if (++tried_targets > opts.target_limit)
break;
/* calculate similarity and see if this pair beats the
* similarity score of the current best pair.
*/
similarity = similarity_measure(
diff, &opts, cache, 2 * i, 2 * j + 1);
if (similarity < 0) {
error = similarity;
goto cleanup;
}
if (to->similarity < (unsigned int)similarity) {
to->similarity = (unsigned int)similarity;
matches[j] = i + 1;
}
}
}
/* next rewrite the diffs with renames / copies */
git_vector_foreach(&diff->deltas, j, to) {
if (!matches[j]) {
assert(to->similarity == 0);
continue;
}
i = matches[j] - 1;
from = GIT_VECTOR_GET(&diff->deltas, i);
assert(from);
/* four possible outcomes here:
* 1. old DELETED and if over rename threshold,
* new becomes RENAMED and old goes away
* 2. old SPLIT and if over rename threshold,
* new becomes RENAMED and old becomes ADDED (clear SPLIT)
* 3. old was MODIFIED but FIND_RENAMES_FROM_REWRITES is on and
* old is more similar to new than it is to itself, in which
* case, new becomes RENAMED and old becomed ADDED
* 4. otherwise if over copy threshold, new becomes COPIED
*/
if (from->status == GIT_DELTA_DELETED) {
if (to->similarity < opts.rename_threshold) {
to->similarity = 0;
continue;
}
to->status = GIT_DELTA_RENAMED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
from->flags |= GIT_DIFF_FLAG__TO_DELETE;
num_rewrites++;
continue;
}
if (from->status == GIT_DELTA_MODIFIED &&
(from->flags & GIT_DIFF_FLAG__TO_SPLIT) != 0)
{
if (to->similarity < opts.rename_threshold) {
to->similarity = 0;
continue;
}
to->status = GIT_DELTA_RENAMED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
from->status = GIT_DELTA_ADDED;
from->flags &= ~GIT_DIFF_FLAG__TO_SPLIT;
memset(&from->old_file, 0, sizeof(from->old_file));
num_rewrites--;
continue;
}
if (from->status == GIT_DELTA_MODIFIED &&
FLAG_SET(opts, GIT_DIFF_FIND_RENAMES_FROM_REWRITES) &&
to->similarity > opts.rename_threshold)
{
similarity = similarity_measure(
diff, &opts, cache, 2 * i, 2 * i + 1);
if (similarity < 0) {
error = similarity;
goto cleanup;
}
if ((unsigned int)similarity < opts.rename_from_rewrite_threshold) {
to->status = GIT_DELTA_RENAMED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
from->status = GIT_DELTA_ADDED;
memset(&from->old_file, 0, sizeof(from->old_file));
from->old_file.path = to->old_file.path;
from->old_file.flags |= GIT_DIFF_FLAG_VALID_OID;
continue;
}
}
if (to->similarity < opts.copy_threshold) {
to->similarity = 0;
continue;
}
/* convert "to" to a COPIED record */
to->status = GIT_DELTA_COPIED;
memcpy(&to->old_file, &from->old_file, sizeof(to->old_file));
}
if (num_rewrites > 0) {
assert(num_rewrites < diff->deltas.length);
error = apply_splits_and_deletes(
diff, diff->deltas.length - num_rewrites);
}
cleanup:
git__free(matches);
for (i = 0; i < cache_size; ++i) {
if (cache[i] != NULL)
opts.metric->free_signature(cache[i], opts.metric->payload);
}
git__free(cache);
if (!given_opts || !given_opts->metric)
git__free(opts.metric);
return error;
}
#undef FLAG_SET
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