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![Alex Riesen](/assets/img/avatar_default.png)
This helps to notice when something's going wrong, especially on systems which lock open files. I used the following criteria when selecting the code for replacement: - it was already printing a warning for the unlink failures - it is in a function which already printing something or is called from such a function - it is in a static function, returning void and the function is only called from a builtin main function (cmd_) - it is in a function which handles emergency exit (signal handlers) - it is in a function which is obvously cleaning up the lockfiles Signed-off-by: Alex Riesen <raa.lkml@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
395 lines
9.3 KiB
C
395 lines
9.3 KiB
C
#include "cache.h"
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#include "string-list.h"
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#include "rerere.h"
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#include "xdiff/xdiff.h"
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#include "xdiff-interface.h"
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/* if rerere_enabled == -1, fall back to detection of .git/rr-cache */
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static int rerere_enabled = -1;
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/* automatically update cleanly resolved paths to the index */
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static int rerere_autoupdate;
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static char *merge_rr_path;
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const char *rerere_path(const char *hex, const char *file)
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{
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return git_path("rr-cache/%s/%s", hex, file);
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}
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int has_rerere_resolution(const char *hex)
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{
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struct stat st;
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return !stat(rerere_path(hex, "postimage"), &st);
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}
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static void read_rr(struct string_list *rr)
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{
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unsigned char sha1[20];
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char buf[PATH_MAX];
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FILE *in = fopen(merge_rr_path, "r");
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if (!in)
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return;
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while (fread(buf, 40, 1, in) == 1) {
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int i;
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char *name;
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if (get_sha1_hex(buf, sha1))
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die("corrupt MERGE_RR");
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buf[40] = '\0';
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name = xstrdup(buf);
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if (fgetc(in) != '\t')
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die("corrupt MERGE_RR");
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for (i = 0; i < sizeof(buf) && (buf[i] = fgetc(in)); i++)
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; /* do nothing */
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if (i == sizeof(buf))
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die("filename too long");
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string_list_insert(buf, rr)->util = name;
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}
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fclose(in);
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}
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static struct lock_file write_lock;
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static int write_rr(struct string_list *rr, int out_fd)
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{
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int i;
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for (i = 0; i < rr->nr; i++) {
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const char *path;
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int length;
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if (!rr->items[i].util)
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continue;
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path = rr->items[i].string;
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length = strlen(path) + 1;
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if (write_in_full(out_fd, rr->items[i].util, 40) != 40 ||
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write_in_full(out_fd, "\t", 1) != 1 ||
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write_in_full(out_fd, path, length) != length)
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die("unable to write rerere record");
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}
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if (commit_lock_file(&write_lock) != 0)
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die("unable to write rerere record");
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return 0;
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}
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static void ferr_write(const void *p, size_t count, FILE *fp, int *err)
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{
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if (!count || *err)
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return;
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if (fwrite(p, count, 1, fp) != 1)
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*err = errno;
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}
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static inline void ferr_puts(const char *s, FILE *fp, int *err)
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{
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ferr_write(s, strlen(s), fp, err);
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}
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static int handle_file(const char *path,
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unsigned char *sha1, const char *output)
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{
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git_SHA_CTX ctx;
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char buf[1024];
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int hunk_no = 0;
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enum {
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RR_CONTEXT = 0, RR_SIDE_1, RR_SIDE_2, RR_ORIGINAL,
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} hunk = RR_CONTEXT;
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struct strbuf one = STRBUF_INIT, two = STRBUF_INIT;
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FILE *f = fopen(path, "r");
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FILE *out = NULL;
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int wrerror = 0;
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if (!f)
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return error("Could not open %s", path);
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if (output) {
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out = fopen(output, "w");
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if (!out) {
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fclose(f);
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return error("Could not write %s", output);
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}
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}
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if (sha1)
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git_SHA1_Init(&ctx);
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while (fgets(buf, sizeof(buf), f)) {
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if (!prefixcmp(buf, "<<<<<<< ")) {
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if (hunk != RR_CONTEXT)
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goto bad;
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hunk = RR_SIDE_1;
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} else if (!prefixcmp(buf, "|||||||") && isspace(buf[7])) {
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if (hunk != RR_SIDE_1)
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goto bad;
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hunk = RR_ORIGINAL;
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} else if (!prefixcmp(buf, "=======") && isspace(buf[7])) {
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if (hunk != RR_SIDE_1 && hunk != RR_ORIGINAL)
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goto bad;
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hunk = RR_SIDE_2;
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} else if (!prefixcmp(buf, ">>>>>>> ")) {
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if (hunk != RR_SIDE_2)
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goto bad;
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if (strbuf_cmp(&one, &two) > 0)
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strbuf_swap(&one, &two);
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hunk_no++;
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hunk = RR_CONTEXT;
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if (out) {
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ferr_puts("<<<<<<<\n", out, &wrerror);
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ferr_write(one.buf, one.len, out, &wrerror);
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ferr_puts("=======\n", out, &wrerror);
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ferr_write(two.buf, two.len, out, &wrerror);
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ferr_puts(">>>>>>>\n", out, &wrerror);
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}
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if (sha1) {
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git_SHA1_Update(&ctx, one.buf ? one.buf : "",
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one.len + 1);
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git_SHA1_Update(&ctx, two.buf ? two.buf : "",
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two.len + 1);
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}
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strbuf_reset(&one);
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strbuf_reset(&two);
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} else if (hunk == RR_SIDE_1)
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strbuf_addstr(&one, buf);
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else if (hunk == RR_ORIGINAL)
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; /* discard */
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else if (hunk == RR_SIDE_2)
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strbuf_addstr(&two, buf);
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else if (out)
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ferr_puts(buf, out, &wrerror);
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continue;
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bad:
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hunk = 99; /* force error exit */
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break;
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}
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strbuf_release(&one);
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strbuf_release(&two);
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fclose(f);
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if (wrerror)
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error("There were errors while writing %s (%s)",
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path, strerror(wrerror));
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if (out && fclose(out))
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wrerror = error("Failed to flush %s: %s",
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path, strerror(errno));
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if (sha1)
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git_SHA1_Final(sha1, &ctx);
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if (hunk != RR_CONTEXT) {
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if (output)
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unlink_or_warn(output);
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return error("Could not parse conflict hunks in %s", path);
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}
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if (wrerror)
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return -1;
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return hunk_no;
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}
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static int find_conflict(struct string_list *conflict)
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{
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int i;
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if (read_cache() < 0)
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return error("Could not read index");
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for (i = 0; i+1 < active_nr; i++) {
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struct cache_entry *e2 = active_cache[i];
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struct cache_entry *e3 = active_cache[i+1];
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if (ce_stage(e2) == 2 &&
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ce_stage(e3) == 3 &&
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ce_same_name(e2, e3) &&
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S_ISREG(e2->ce_mode) &&
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S_ISREG(e3->ce_mode)) {
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string_list_insert((const char *)e2->name, conflict);
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i++; /* skip over both #2 and #3 */
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}
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}
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return 0;
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}
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static int merge(const char *name, const char *path)
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{
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int ret;
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mmfile_t cur, base, other;
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mmbuffer_t result = {NULL, 0};
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xpparam_t xpp = {XDF_NEED_MINIMAL};
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if (handle_file(path, NULL, rerere_path(name, "thisimage")) < 0)
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return 1;
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if (read_mmfile(&cur, rerere_path(name, "thisimage")) ||
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read_mmfile(&base, rerere_path(name, "preimage")) ||
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read_mmfile(&other, rerere_path(name, "postimage")))
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return 1;
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ret = xdl_merge(&base, &cur, "", &other, "",
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&xpp, XDL_MERGE_ZEALOUS, &result);
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if (!ret) {
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FILE *f = fopen(path, "w");
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if (!f)
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return error("Could not open %s: %s", path,
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strerror(errno));
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if (fwrite(result.ptr, result.size, 1, f) != 1)
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error("Could not write %s: %s", path, strerror(errno));
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if (fclose(f))
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return error("Writing %s failed: %s", path,
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strerror(errno));
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}
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free(cur.ptr);
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free(base.ptr);
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free(other.ptr);
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free(result.ptr);
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return ret;
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}
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static struct lock_file index_lock;
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static int update_paths(struct string_list *update)
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{
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int i;
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int fd = hold_locked_index(&index_lock, 0);
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int status = 0;
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if (fd < 0)
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return -1;
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for (i = 0; i < update->nr; i++) {
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struct string_list_item *item = &update->items[i];
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if (add_file_to_cache(item->string, ADD_CACHE_IGNORE_ERRORS))
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status = -1;
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}
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if (!status && active_cache_changed) {
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if (write_cache(fd, active_cache, active_nr) ||
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commit_locked_index(&index_lock))
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die("Unable to write new index file");
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} else if (fd >= 0)
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rollback_lock_file(&index_lock);
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return status;
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}
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static int do_plain_rerere(struct string_list *rr, int fd)
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{
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struct string_list conflict = { NULL, 0, 0, 1 };
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struct string_list update = { NULL, 0, 0, 1 };
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int i;
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find_conflict(&conflict);
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/*
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* MERGE_RR records paths with conflicts immediately after merge
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* failed. Some of the conflicted paths might have been hand resolved
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* in the working tree since then, but the initial run would catch all
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* and register their preimages.
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*/
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for (i = 0; i < conflict.nr; i++) {
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const char *path = conflict.items[i].string;
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if (!string_list_has_string(rr, path)) {
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unsigned char sha1[20];
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char *hex;
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int ret;
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ret = handle_file(path, sha1, NULL);
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if (ret < 1)
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continue;
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hex = xstrdup(sha1_to_hex(sha1));
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string_list_insert(path, rr)->util = hex;
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if (mkdir(git_path("rr-cache/%s", hex), 0755))
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continue;
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handle_file(path, NULL, rerere_path(hex, "preimage"));
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fprintf(stderr, "Recorded preimage for '%s'\n", path);
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}
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}
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/*
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* Now some of the paths that had conflicts earlier might have been
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* hand resolved. Others may be similar to a conflict already that
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* was resolved before.
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*/
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for (i = 0; i < rr->nr; i++) {
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int ret;
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const char *path = rr->items[i].string;
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const char *name = (const char *)rr->items[i].util;
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if (has_rerere_resolution(name)) {
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if (!merge(name, path)) {
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if (rerere_autoupdate)
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string_list_insert(path, &update);
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fprintf(stderr,
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"%s '%s' using previous resolution.\n",
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rerere_autoupdate
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? "Staged" : "Resolved",
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path);
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goto mark_resolved;
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}
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}
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/* Let's see if we have resolved it. */
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ret = handle_file(path, NULL, NULL);
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if (ret)
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continue;
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fprintf(stderr, "Recorded resolution for '%s'.\n", path);
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copy_file(rerere_path(name, "postimage"), path, 0666);
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mark_resolved:
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rr->items[i].util = NULL;
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}
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if (update.nr)
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update_paths(&update);
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return write_rr(rr, fd);
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}
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static int git_rerere_config(const char *var, const char *value, void *cb)
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{
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if (!strcmp(var, "rerere.enabled"))
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rerere_enabled = git_config_bool(var, value);
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else if (!strcmp(var, "rerere.autoupdate"))
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rerere_autoupdate = git_config_bool(var, value);
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else
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return git_default_config(var, value, cb);
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return 0;
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}
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static int is_rerere_enabled(void)
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{
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const char *rr_cache;
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int rr_cache_exists;
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if (!rerere_enabled)
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return 0;
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rr_cache = git_path("rr-cache");
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rr_cache_exists = is_directory(rr_cache);
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if (rerere_enabled < 0)
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return rr_cache_exists;
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if (!rr_cache_exists &&
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(mkdir(rr_cache, 0777) || adjust_shared_perm(rr_cache)))
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die("Could not create directory %s", rr_cache);
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return 1;
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}
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int setup_rerere(struct string_list *merge_rr)
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{
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int fd;
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git_config(git_rerere_config, NULL);
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if (!is_rerere_enabled())
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return -1;
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merge_rr_path = git_pathdup("MERGE_RR");
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fd = hold_lock_file_for_update(&write_lock, merge_rr_path,
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LOCK_DIE_ON_ERROR);
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read_rr(merge_rr);
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return fd;
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}
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int rerere(void)
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{
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struct string_list merge_rr = { NULL, 0, 0, 1 };
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int fd;
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fd = setup_rerere(&merge_rr);
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if (fd < 0)
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return 0;
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return do_plain_rerere(&merge_rr, fd);
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}
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