diff options
Diffstat (limited to 'blame.c')
| -rw-r--r-- | blame.c | 442 |
1 files changed, 442 insertions, 0 deletions
diff --git a/blame.c b/blame.c new file mode 100644 index 000000000..dbce7e2c5 --- /dev/null +++ b/blame.c @@ -0,0 +1,442 @@ +#include <assert.h> + +#include "cache.h" +#include "refs.h" +#include "tag.h" +#include "commit.h" +#include "tree.h" +#include "blob.h" +#include "diff.h" + +#define DEBUG 0 + +struct commit** blame_lines; +int num_blame_lines; + +struct util_info +{ + int* line_map; + int num_lines; + unsigned char sha1[20]; /* blob sha, not commit! */ + char* buf; + unsigned long size; +// const char* path; +}; + +struct chunk +{ + int off1, len1; // --- + int off2, len2; // +++ +}; + +struct patch +{ + struct chunk* chunks; + int num; +}; + +static void get_blob(struct commit* commit); + +int num_get_patch = 0; +int num_commits = 0; + +struct patch* get_patch(struct commit* commit, struct commit* other) +{ + struct patch* ret = xmalloc(sizeof(struct patch)); + ret->chunks = NULL; + ret->num = 0; + + struct util_info* info_c = (struct util_info*) commit->object.util; + struct util_info* info_o = (struct util_info*) other->object.util; + + if(!memcmp(info_c->sha1, info_o->sha1, 20)) + return ret; + + get_blob(commit); + get_blob(other); + + FILE* fout = fopen("/tmp/git-blame-tmp1", "w"); + if(!fout) + die("fopen tmp1 failed: %s", strerror(errno)); + + if(fwrite(info_c->buf, info_c->size, 1, fout) != 1) + die("fwrite 1 failed: %s", strerror(errno)); + fclose(fout); + + fout = fopen("/tmp/git-blame-tmp2", "w"); + if(!fout) + die("fopen tmp2 failed: %s", strerror(errno)); + + if(fwrite(info_o->buf, info_o->size, 1, fout) != 1) + die("fwrite 2 failed: %s", strerror(errno)); + fclose(fout); + + FILE* fin = popen("diff -u0 /tmp/git-blame-tmp1 /tmp/git-blame-tmp2", "r"); + if(!fin) + die("popen failed: %s", strerror(errno)); + + char buf[1024]; + while(fgets(buf, sizeof(buf), fin)) { + if(buf[0] != '@' || buf[1] != '@') + continue; + + if(DEBUG) + printf("chunk line: %s", buf); + ret->num++; + ret->chunks = xrealloc(ret->chunks, sizeof(struct chunk)*ret->num); + struct chunk* chunk = &ret->chunks[ret->num-1]; + + assert(!strncmp(buf, "@@ -", 4)); + + char* start = buf+4; + char* sp = index(start, ' '); + *sp = '\0'; + if(index(start, ',')) { + int ret = sscanf(start, "%d,%d", &chunk->off1, &chunk->len1); + assert(ret == 2); + } else { + int ret = sscanf(start, "%d", &chunk->off1); + assert(ret == 1); + chunk->len1 = 1; + } + *sp = ' '; + + start = sp+1; + sp = index(start, ' '); + *sp = '\0'; + if(index(start, ',')) { + int ret = sscanf(start, "%d,%d", &chunk->off2, &chunk->len2); + assert(ret == 2); + } else { + int ret = sscanf(start, "%d", &chunk->off2); + assert(ret == 1); + chunk->len2 = 1; + } + *sp = ' '; + + if(chunk->off1 > 0) + chunk->off1 -= 1; + if(chunk->off2 > 0) + chunk->off2 -= 1; + + assert(chunk->off1 >= 0); + assert(chunk->off2 >= 0); + } + fclose(fin); + + num_get_patch++; + return ret; +} + +void free_patch(struct patch* p) +{ + free(p->chunks); + free(p); +} + +static int get_blob_sha1_internal(unsigned char *sha1, const char *base, int baselen, + const char *pathname, unsigned mode, int stage); + + +static unsigned char blob_sha1[20]; +static int get_blob_sha1(struct tree* t, const char* pathname, unsigned char* sha1) +{ + const char *pathspec[2]; + pathspec[0] = pathname; + pathspec[1] = NULL; + memset(blob_sha1, 0, sizeof(blob_sha1)); + read_tree_recursive(t, "", 0, 0, pathspec, get_blob_sha1_internal); + + int i; + for(i = 0; i < 20; i++) { + if(blob_sha1[i] != 0) + break; + } + + if(i == 20) + return -1; + + memcpy(sha1, blob_sha1, 20); + return 0; +} + +static int get_blob_sha1_internal(unsigned char *sha1, const char *base, int baselen, + const char *pathname, unsigned mode, int stage) +{ +// printf("Got blob: %s base: '%s' baselen: %d pathname: '%s' mode: %o stage: %d\n", +// sha1_to_hex(sha1), base, baselen, pathname, mode, stage); + + if(S_ISDIR(mode)) + return READ_TREE_RECURSIVE; + + memcpy(blob_sha1, sha1, 20); + return -1; +} + +static void get_blob(struct commit* commit) +{ + struct util_info* info = commit->object.util; + char type[20]; + + if(info->buf) + return; + + info->buf = read_sha1_file(info->sha1, type, &info->size); + assert(!strcmp(type, "blob")); +} + +void print_patch(struct patch* p) +{ + printf("Num chunks: %d\n", p->num); + int i; + for(i = 0; i < p->num; i++) { + printf("%d,%d %d,%d\n", p->chunks[i].off1, p->chunks[i].len1, p->chunks[i].off2, p->chunks[i].len2); + } +} + + +// p is a patch from commit to other. +void fill_line_map(struct commit* commit, struct commit* other, struct patch* p) +{ + int num_lines = ((struct util_info*) commit->object.util)->num_lines; + int* line_map = ((struct util_info*) commit->object.util)->line_map; + int num_lines2 = ((struct util_info*) other->object.util)->num_lines; + int* line_map2 = ((struct util_info*) other->object.util)->line_map; + int cur_chunk = 0; + int i1, i2; + + if(p->num && DEBUG) + print_patch(p); + + for(i1 = 0; i1 < num_lines; i1++) + line_map[i1] = -1; + + if(DEBUG) + printf("num lines 1: %d num lines 2: %d\n", num_lines, num_lines2); + + for(i1 = 0, i2 = 0; i1 < num_lines; i1++, i2++) { + if(DEBUG > 1) + printf("%d %d\n", i1, i2); + + if(i2 >= num_lines2) + break; + + line_map[i1] = line_map2[i2]; + + struct chunk* chunk = NULL; + if(cur_chunk < p->num) + chunk = &p->chunks[cur_chunk]; + + if(chunk && chunk->off1 == i1) { + i2 = chunk->off2; + + if(chunk->len1 > 0) + i1 += chunk->len1-1; + if(chunk->len2 > 0) + i2 += chunk->len2-1; + cur_chunk++; + } + } +} + +int map_line(struct commit* commit, int line) +{ + struct util_info* info = commit->object.util; + assert(line >= 0 && line < info->num_lines); + return info->line_map[line]; +} + +int fill_util_info(struct commit* commit, const char* path) +{ + if(commit->object.util) + return 0; + + struct util_info* util = xmalloc(sizeof(struct util_info)); + util->buf = NULL; + util->size = 0; + util->num_lines = -1; + util->line_map = NULL; + + commit->object.util = util; + + if(get_blob_sha1(commit->tree, path, util->sha1)) + return -1; + + return 0; +} + +void alloc_line_map(struct commit* commit) +{ + struct util_info* util = commit->object.util; + + if(util->line_map) + return; + + get_blob(commit); + + int i; + util->num_lines = 0; + for(i = 0; i < util->size; i++) { + if(util->buf[i] == '\n') + util->num_lines++; + } + util->line_map = xmalloc(sizeof(int)*util->num_lines); +} + +void copy_line_map(struct commit* dst, struct commit* src) +{ + struct util_info* u_dst = dst->object.util; + struct util_info* u_src = src->object.util; + + u_dst->line_map = u_src->line_map; + u_dst->num_lines = u_src->num_lines; + u_dst->buf = u_src->buf; + u_dst->size = u_src->size; +} + +void process_commits(struct commit_list* list, const char* path) +{ + int i; + + while(list) { + struct commit* commit = pop_commit(&list); + struct commit_list* parents; + struct util_info* info; + + info = commit->object.util; + num_commits++; + if(DEBUG) + printf("\nProcessing commit: %d %s\n", num_commits, sha1_to_hex(commit->object.sha1)); + for(parents = commit->parents; + parents != NULL; parents = parents->next) { + struct commit* parent = parents->item; + + if(parse_commit(parent) < 0) + die("parse_commit error"); + + if(DEBUG) + printf("parent: %s\n", sha1_to_hex(parent->object.sha1)); + + if(fill_util_info(parent, path)) + continue; + + // Temporarily assign everything to the parent. + int num_blame = 0; + for(i = 0; i < num_blame_lines; i++) { + if(blame_lines[i] == commit) { + num_blame++; + blame_lines[i] = parent; + } + } + + if(num_blame == 0) + continue; + + struct patch* patch = get_patch(parent, commit); + if(patch->num == 0) { + copy_line_map(parent, commit); + } else { + alloc_line_map(parent); + fill_line_map(parent, commit, patch); + } + + for(i = 0; i < patch->num; i++) { + int l; + for(l = 0; l < patch->chunks[i].len2; l++) { + int mapped_line = map_line(commit, patch->chunks[i].off2 + l); + if(mapped_line != -1 && blame_lines[mapped_line] == parent) + blame_lines[mapped_line] = commit; + } + } + free_patch(patch); + } + } +} + +#define SEEN 1 +struct commit_list* get_commit_list(struct commit* commit, const char* pathname) +{ + struct commit_list* ret = NULL; + struct commit_list* process = NULL; + unsigned char sha1[20]; + + commit_list_insert(commit, &process); + + while(process) { + struct commit* com = pop_commit(&process); + if(com->object.flags & SEEN) + continue; + + com->object.flags |= SEEN; + commit_list_insert(com, &ret); + struct commit_list* parents; + + parse_commit(com); + + for(parents = com->parents; + parents != NULL; parents = parents->next) { + struct commit* parent = parents->item; + + parse_commit(parent); + + if(!get_blob_sha1(parent->tree, pathname, sha1)) + commit_list_insert(parent, &process); + } + } + + return ret; +} + +int main(int argc, const char **argv) +{ + unsigned char sha1[20]; + struct commit *commit; + const char* filename; + int i; + + setup_git_directory(); + + if (argc != 3) + die("Usage: blame commit-ish file"); + + if (get_sha1(argv[1], sha1)) + die("get_sha1 failed"); + + commit = lookup_commit_reference(sha1); + + filename = argv[2]; + + struct commit_list* list = get_commit_list(commit, filename); + sort_in_topological_order(&list, 1); + + if(fill_util_info(commit, filename)) { + printf("%s not found in %s\n", filename, argv[1]); + return 0; + } + alloc_line_map(commit); + + struct util_info* util = commit->object.util; + num_blame_lines = util->num_lines; + blame_lines = xmalloc(sizeof(struct commit*)*num_blame_lines); + + + for(i = 0; i < num_blame_lines; i++) { + blame_lines[i] = commit; + + ((struct util_info*) commit->object.util)->line_map[i] = i; + } + + process_commits(list, filename); + + for(i = 0; i < num_blame_lines; i++) { + printf("%d %s\n", i+1-1, sha1_to_hex(blame_lines[i]->object.sha1)); +// printf("%d %s\n", i+1-1, find_unique_abbrev(blame_lines[i]->object.sha1, 6)); + } + + if(DEBUG) { + printf("num get patch: %d\n", num_get_patch); + printf("num commits: %d\n", num_commits); + } + + return 0; +} |