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author | Edward Thomson <ethomson@edwardthomson.com> | 2021-11-14 08:47:40 -0500 |
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committer | Edward Thomson <ethomson@edwardthomson.com> | 2022-02-22 22:07:44 -0500 |
commit | ef4ab2988320005cbcb3db920e6b41f10b3c60cf (patch) | |
tree | 6609f213ad9d607e8df1f543919d3154c056c3ef /src/libgit2/merge_file.c | |
parent | 49e180c862dc7c6d1f62a53bf8756e25b3417968 (diff) | |
download | libgit2-ef4ab2988320005cbcb3db920e6b41f10b3c60cf.tar.gz |
refactor: `src` is now `src/libgit2`
Diffstat (limited to 'src/libgit2/merge_file.c')
-rw-r--r-- | src/libgit2/merge_file.c | 327 |
1 files changed, 327 insertions, 0 deletions
diff --git a/src/libgit2/merge_file.c b/src/libgit2/merge_file.c new file mode 100644 index 000000000..732a047b1 --- /dev/null +++ b/src/libgit2/merge_file.c @@ -0,0 +1,327 @@ +/* + * 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 "repository.h" +#include "posix.h" +#include "futils.h" +#include "index.h" +#include "diff_xdiff.h" +#include "merge.h" + +#include "git2/repository.h" +#include "git2/object.h" +#include "git2/index.h" +#include "git2/merge.h" + +#include "xdiff/xdiff.h" + +/* only examine the first 8000 bytes for binaryness. + * https://github.com/git/git/blob/77bd3ea9f54f1584147b594abc04c26ca516d987/xdiff-interface.c#L197 + */ +#define GIT_MERGE_FILE_BINARY_SIZE 8000 + +#define GIT_MERGE_FILE_SIDE_EXISTS(X) ((X)->mode != 0) + +static int merge_file_input_from_index( + git_merge_file_input *input_out, + git_odb_object **odb_object_out, + git_odb *odb, + const git_index_entry *entry) +{ + int error = 0; + + GIT_ASSERT_ARG(input_out); + GIT_ASSERT_ARG(odb_object_out); + GIT_ASSERT_ARG(odb); + GIT_ASSERT_ARG(entry); + + if ((error = git_odb_read(odb_object_out, odb, &entry->id)) < 0) + goto done; + + input_out->path = entry->path; + input_out->mode = entry->mode; + input_out->ptr = (char *)git_odb_object_data(*odb_object_out); + input_out->size = git_odb_object_size(*odb_object_out); + +done: + return error; +} + +static void merge_file_normalize_opts( + git_merge_file_options *out, + const git_merge_file_options *given_opts) +{ + if (given_opts) + memcpy(out, given_opts, sizeof(git_merge_file_options)); + else { + git_merge_file_options default_opts = GIT_MERGE_FILE_OPTIONS_INIT; + memcpy(out, &default_opts, sizeof(git_merge_file_options)); + } +} + +static int merge_file__xdiff( + git_merge_file_result *out, + const git_merge_file_input *ancestor, + const git_merge_file_input *ours, + const git_merge_file_input *theirs, + const git_merge_file_options *given_opts) +{ + xmparam_t xmparam; + mmfile_t ancestor_mmfile = {0}, our_mmfile = {0}, their_mmfile = {0}; + mmbuffer_t mmbuffer; + git_merge_file_options options = GIT_MERGE_FILE_OPTIONS_INIT; + const char *path; + int xdl_result; + int error = 0; + + memset(out, 0x0, sizeof(git_merge_file_result)); + + merge_file_normalize_opts(&options, given_opts); + + memset(&xmparam, 0x0, sizeof(xmparam_t)); + + if (ours->size > LONG_MAX || + theirs->size > LONG_MAX || + (ancestor && ancestor->size > LONG_MAX)) { + git_error_set(GIT_ERROR_MERGE, "failed to merge files"); + error = -1; + goto done; + } + + if (ancestor) { + xmparam.ancestor = (options.ancestor_label) ? + options.ancestor_label : ancestor->path; + ancestor_mmfile.ptr = (char *)ancestor->ptr; + ancestor_mmfile.size = (long)ancestor->size; + } + + xmparam.file1 = (options.our_label) ? + options.our_label : ours->path; + our_mmfile.ptr = (char *)ours->ptr; + our_mmfile.size = (long)ours->size; + + xmparam.file2 = (options.their_label) ? + options.their_label : theirs->path; + their_mmfile.ptr = (char *)theirs->ptr; + their_mmfile.size = (long)theirs->size; + + if (options.favor == GIT_MERGE_FILE_FAVOR_OURS) + xmparam.favor = XDL_MERGE_FAVOR_OURS; + else if (options.favor == GIT_MERGE_FILE_FAVOR_THEIRS) + xmparam.favor = XDL_MERGE_FAVOR_THEIRS; + else if (options.favor == GIT_MERGE_FILE_FAVOR_UNION) + xmparam.favor = XDL_MERGE_FAVOR_UNION; + + xmparam.level = (options.flags & GIT_MERGE_FILE_SIMPLIFY_ALNUM) ? + XDL_MERGE_ZEALOUS_ALNUM : XDL_MERGE_ZEALOUS; + + if (options.flags & GIT_MERGE_FILE_STYLE_DIFF3) + xmparam.style = XDL_MERGE_DIFF3; + if (options.flags & GIT_MERGE_FILE_STYLE_ZDIFF3) + xmparam.style = XDL_MERGE_ZEALOUS_DIFF3; + + if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE) + xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE; + if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_CHANGE) + xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE_CHANGE; + if (options.flags & GIT_MERGE_FILE_IGNORE_WHITESPACE_EOL) + xmparam.xpp.flags |= XDF_IGNORE_WHITESPACE_AT_EOL; + + if (options.flags & GIT_MERGE_FILE_DIFF_PATIENCE) + xmparam.xpp.flags |= XDF_PATIENCE_DIFF; + + if (options.flags & GIT_MERGE_FILE_DIFF_MINIMAL) + xmparam.xpp.flags |= XDF_NEED_MINIMAL; + + xmparam.marker_size = options.marker_size; + + if ((xdl_result = xdl_merge(&ancestor_mmfile, &our_mmfile, + &their_mmfile, &xmparam, &mmbuffer)) < 0) { + git_error_set(GIT_ERROR_MERGE, "failed to merge files"); + error = -1; + goto done; + } + + path = git_merge_file__best_path( + ancestor ? ancestor->path : NULL, + ours->path, + theirs->path); + + if (path != NULL && (out->path = git__strdup(path)) == NULL) { + error = -1; + goto done; + } + + out->automergeable = (xdl_result == 0); + out->ptr = (const char *)mmbuffer.ptr; + out->len = mmbuffer.size; + out->mode = git_merge_file__best_mode( + ancestor ? ancestor->mode : 0, + ours->mode, + theirs->mode); + +done: + if (error < 0) + git_merge_file_result_free(out); + + return error; +} + +static bool merge_file__is_binary(const git_merge_file_input *file) +{ + size_t len = file ? file->size : 0; + + if (len > GIT_XDIFF_MAX_SIZE) + return true; + if (len > GIT_MERGE_FILE_BINARY_SIZE) + len = GIT_MERGE_FILE_BINARY_SIZE; + + return len ? (memchr(file->ptr, 0, len) != NULL) : false; +} + +static int merge_file__binary( + git_merge_file_result *out, + const git_merge_file_input *ours, + const git_merge_file_input *theirs, + const git_merge_file_options *given_opts) +{ + const git_merge_file_input *favored = NULL; + + memset(out, 0x0, sizeof(git_merge_file_result)); + + if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_OURS) + favored = ours; + else if (given_opts && given_opts->favor == GIT_MERGE_FILE_FAVOR_THEIRS) + favored = theirs; + else + goto done; + + if ((out->path = git__strdup(favored->path)) == NULL || + (out->ptr = git__malloc(favored->size)) == NULL) + goto done; + + memcpy((char *)out->ptr, favored->ptr, favored->size); + out->len = favored->size; + out->mode = favored->mode; + out->automergeable = 1; + +done: + return 0; +} + +static int merge_file__from_inputs( + git_merge_file_result *out, + const git_merge_file_input *ancestor, + const git_merge_file_input *ours, + const git_merge_file_input *theirs, + const git_merge_file_options *given_opts) +{ + if (merge_file__is_binary(ancestor) || + merge_file__is_binary(ours) || + merge_file__is_binary(theirs)) + return merge_file__binary(out, ours, theirs, given_opts); + + return merge_file__xdiff(out, ancestor, ours, theirs, given_opts); +} + +static git_merge_file_input *git_merge_file__normalize_inputs( + git_merge_file_input *out, + const git_merge_file_input *given) +{ + memcpy(out, given, sizeof(git_merge_file_input)); + + if (!out->path) + out->path = "file.txt"; + + if (!out->mode) + out->mode = 0100644; + + return out; +} + +int git_merge_file( + git_merge_file_result *out, + const git_merge_file_input *ancestor, + const git_merge_file_input *ours, + const git_merge_file_input *theirs, + const git_merge_file_options *options) +{ + git_merge_file_input inputs[3] = { {0} }; + + GIT_ASSERT_ARG(out); + GIT_ASSERT_ARG(ours); + GIT_ASSERT_ARG(theirs); + + memset(out, 0x0, sizeof(git_merge_file_result)); + + if (ancestor) + ancestor = git_merge_file__normalize_inputs(&inputs[0], ancestor); + + ours = git_merge_file__normalize_inputs(&inputs[1], ours); + theirs = git_merge_file__normalize_inputs(&inputs[2], theirs); + + return merge_file__from_inputs(out, ancestor, ours, theirs, options); +} + +int git_merge_file_from_index( + git_merge_file_result *out, + git_repository *repo, + const git_index_entry *ancestor, + const git_index_entry *ours, + const git_index_entry *theirs, + const git_merge_file_options *options) +{ + git_merge_file_input *ancestor_ptr = NULL, + ancestor_input = {0}, our_input = {0}, their_input = {0}; + git_odb *odb = NULL; + git_odb_object *odb_object[3] = { 0 }; + int error = 0; + + GIT_ASSERT_ARG(out); + GIT_ASSERT_ARG(repo); + GIT_ASSERT_ARG(ours); + GIT_ASSERT_ARG(theirs); + + memset(out, 0x0, sizeof(git_merge_file_result)); + + if ((error = git_repository_odb(&odb, repo)) < 0) + goto done; + + if (ancestor) { + if ((error = merge_file_input_from_index( + &ancestor_input, &odb_object[0], odb, ancestor)) < 0) + goto done; + + ancestor_ptr = &ancestor_input; + } + + if ((error = merge_file_input_from_index(&our_input, &odb_object[1], odb, ours)) < 0 || + (error = merge_file_input_from_index(&their_input, &odb_object[2], odb, theirs)) < 0) + goto done; + + error = merge_file__from_inputs(out, + ancestor_ptr, &our_input, &their_input, options); + +done: + git_odb_object_free(odb_object[0]); + git_odb_object_free(odb_object[1]); + git_odb_object_free(odb_object[2]); + git_odb_free(odb); + + return error; +} + +void git_merge_file_result_free(git_merge_file_result *result) +{ + if (result == NULL) + return; + + git__free((char *)result->path); + git__free((char *)result->ptr); +} |