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git/blame.c
Junio C Hamano 1025fe51bf Merge branch 'lt/rev-list' into next
* lt/rev-list:
  Rip out merge-order and make "git log <paths>..." work again.
  Tie it all together: "git log"
  Introduce trivial new pager.c helper infrastructure
  git-rev-list libification: rev-list walking

blame.c #include's epoch.h; it needed to be killed.
2006-03-01 02:55:56 -08:00

442 lines
11 KiB
C

#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;
}