]> git.ipfire.org Git - thirdparty/git.git/blobdiff - server-info.c
Merge branch 'jt/t5500-unflake'
[thirdparty/git.git] / server-info.c
index e2b2d6a27a40b1a3683dd99459c0fab0d45dc0c9..bae2cdfd5127e42ca66622270326d8094fe13f40 100644 (file)
@@ -1,4 +1,5 @@
 #include "cache.h"
+#include "dir.h"
 #include "repository.h"
 #include "refs.h"
 #include "object.h"
 #include "tag.h"
 #include "packfile.h"
 #include "object-store.h"
+#include "strbuf.h"
+
+struct update_info_ctx {
+       FILE *cur_fp;
+       FILE *old_fp; /* becomes NULL if it differs from cur_fp */
+       struct strbuf cur_sb;
+       struct strbuf old_sb;
+};
+
+static void uic_mark_stale(struct update_info_ctx *uic)
+{
+       fclose(uic->old_fp);
+       uic->old_fp = NULL;
+}
+
+static int uic_is_stale(const struct update_info_ctx *uic)
+{
+       return uic->old_fp == NULL;
+}
+
+static int uic_printf(struct update_info_ctx *uic, const char *fmt, ...)
+{
+       va_list ap;
+       int ret = -1;
+
+       va_start(ap, fmt);
+
+       if (uic_is_stale(uic)) {
+               ret = vfprintf(uic->cur_fp, fmt, ap);
+       } else {
+               ssize_t r;
+               struct strbuf *cur = &uic->cur_sb;
+               struct strbuf *old = &uic->old_sb;
+
+               strbuf_reset(cur);
+               strbuf_vinsertf(cur, 0, fmt, ap);
+
+               strbuf_reset(old);
+               strbuf_grow(old, cur->len);
+               r = fread(old->buf, 1, cur->len, uic->old_fp);
+               if (r != cur->len || memcmp(old->buf, cur->buf, r))
+                       uic_mark_stale(uic);
+
+               if (fwrite(cur->buf, 1, cur->len, uic->cur_fp) == cur->len)
+                       ret = 0;
+       }
+
+       va_end(ap);
+
+       return ret;
+}
 
 /*
  * Create the file "path" by writing to a temporary file and renaming
  * it into place. The contents of the file come from "generate", which
  * should return non-zero if it encounters an error.
  */
-static int update_info_file(char *path, int (*generate)(FILE *))
+static int update_info_file(char *path,
+                       int (*generate)(struct update_info_ctx *),
+                       int force)
 {
        char *tmp = mkpathdup("%s_XXXXXX", path);
        int ret = -1;
        int fd = -1;
-       FILE *fp = NULL, *to_close;
+       FILE *to_close;
+       struct update_info_ctx uic = {
+               .cur_fp = NULL,
+               .old_fp = NULL,
+               .cur_sb = STRBUF_INIT,
+               .old_sb = STRBUF_INIT
+       };
 
        safe_create_leading_directories(path);
        fd = git_mkstemp_mode(tmp, 0666);
        if (fd < 0)
                goto out;
-       to_close = fp = fdopen(fd, "w");
-       if (!fp)
+       to_close = uic.cur_fp = fdopen(fd, "w");
+       if (!uic.cur_fp)
                goto out;
        fd = -1;
-       ret = generate(fp);
+
+       /* no problem on ENOENT and old_fp == NULL, it's stale, now */
+       if (!force)
+               uic.old_fp = fopen_or_warn(path, "r");
+
+       /*
+        * uic_printf will compare incremental comparison against old_fp
+        * and mark uic as stale if needed
+        */
+       ret = generate(&uic);
        if (ret)
                goto out;
-       fp = NULL;
+
+       /* new file may be shorter than the old one, check here */
+       if (!uic_is_stale(&uic)) {
+               struct stat st;
+               long new_len = ftell(uic.cur_fp);
+               int old_fd = fileno(uic.old_fp);
+
+               if (new_len < 0) {
+                       ret = -1;
+                       goto out;
+               }
+               if (fstat(old_fd, &st) || (st.st_size != (size_t)new_len))
+                       uic_mark_stale(&uic);
+       }
+
+       uic.cur_fp = NULL;
        if (fclose(to_close))
                goto out;
-       if (adjust_shared_perm(tmp) < 0)
-               goto out;
-       if (rename(tmp, path) < 0)
-               goto out;
+
+       if (uic_is_stale(&uic)) {
+               if (adjust_shared_perm(tmp) < 0)
+                       goto out;
+               if (rename(tmp, path) < 0)
+                       goto out;
+       } else {
+               unlink(tmp);
+       }
        ret = 0;
 
 out:
        if (ret) {
                error_errno("unable to update %s", path);
-               if (fp)
-                       fclose(fp);
+               if (uic.cur_fp)
+                       fclose(uic.cur_fp);
                else if (fd >= 0)
                        close(fd);
                unlink(tmp);
        }
        free(tmp);
+       if (uic.old_fp)
+               fclose(uic.old_fp);
+       strbuf_release(&uic.old_sb);
+       strbuf_release(&uic.cur_sb);
        return ret;
 }
 
 static int add_info_ref(const char *path, const struct object_id *oid,
                        int flag, void *cb_data)
 {
-       FILE *fp = cb_data;
+       struct update_info_ctx *uic = cb_data;
        struct object *o = parse_object(the_repository, oid);
        if (!o)
                return -1;
 
-       if (fprintf(fp, "%s     %s\n", oid_to_hex(oid), path) < 0)
+       if (uic_printf(uic, "%s %s\n", oid_to_hex(oid), path) < 0)
                return -1;
 
        if (o->type == OBJ_TAG) {
                o = deref_tag(the_repository, o, path, 0);
                if (o)
-                       if (fprintf(fp, "%s     %s^{}\n",
+                       if (uic_printf(uic, "%s %s^{}\n",
                                oid_to_hex(&o->oid), path) < 0)
                                return -1;
        }
        return 0;
 }
 
-static int generate_info_refs(FILE *fp)
+static int generate_info_refs(struct update_info_ctx *uic)
 {
-       return for_each_ref(add_info_ref, fp);
+       return for_each_ref(add_info_ref, uic);
 }
 
 static int update_info_refs(int force)
 {
        char *path = git_pathdup("info/refs");
-       int ret = update_info_file(path, generate_info_refs);
+       int ret = update_info_file(path, generate_info_refs, force);
        free(path);
        return ret;
 }
@@ -91,19 +184,15 @@ static struct pack_info {
        struct packed_git *p;
        int old_num;
        int new_num;
-       int nr_alloc;
 } **info;
 static int num_pack;
-static const char *objdir;
-static int objdirlen;
 
 static struct pack_info *find_pack_by_name(const char *name)
 {
        int i;
        for (i = 0; i < num_pack; i++) {
                struct packed_git *p = info[i]->p;
-               /* skip "/pack/" after ".git/objects" */
-               if (!strcmp(p->pack_name + objdirlen + 6, name))
+               if (!strcmp(pack_basename(p), name))
                        return info[i];
        }
        return NULL;
@@ -112,9 +201,9 @@ static struct pack_info *find_pack_by_name(const char *name)
 /* Returns non-zero when we detect that the info in the
  * old file is useless.
  */
-static int parse_pack_def(const char *line, int old_cnt)
+static int parse_pack_def(const char *packname, int old_cnt)
 {
-       struct pack_info *i = find_pack_by_name(line + 2);
+       struct pack_info *i = find_pack_by_name(packname);
        if (i) {
                i->old_num = old_cnt;
                return 0;
@@ -131,39 +220,40 @@ static int parse_pack_def(const char *line, int old_cnt)
 static int read_pack_info_file(const char *infofile)
 {
        FILE *fp;
-       char line[1000];
+       struct strbuf line = STRBUF_INIT;
        int old_cnt = 0;
+       int stale = 1;
 
        fp = fopen_or_warn(infofile, "r");
        if (!fp)
                return 1; /* nonexistent is not an error. */
 
-       while (fgets(line, sizeof(line), fp)) {
-               int len = strlen(line);
-               if (len && line[len-1] == '\n')
-                       line[--len] = 0;
+       while (strbuf_getline(&line, fp) != EOF) {
+               const char *arg;
 
-               if (!len)
+               if (!line.len)
                        continue;
 
-               switch (line[0]) {
-               case 'P': /* P name */
-                       if (parse_pack_def(line, old_cnt++))
+               if (skip_prefix(line.buf, "P ", &arg)) {
+                       /* P name */
+                       if (parse_pack_def(arg, old_cnt++))
                                goto out_stale;
-                       break;
-               case 'D': /* we used to emit D but that was misguided. */
-               case 'T': /* we used to emit T but nobody uses it. */
+               } else if (line.buf[0] == 'D') {
+                       /* we used to emit D but that was misguided. */
+                       goto out_stale;
+               } else if (line.buf[0] == 'T') {
+                       /* we used to emit T but nobody uses it. */
                        goto out_stale;
-               default:
-                       error("unrecognized: %s", line);
-                       break;
+               } else {
+                       error("unrecognized: %s", line.buf);
                }
        }
-       fclose(fp);
-       return 0;
+       stale = 0;
+
  out_stale:
+       strbuf_release(&line);
        fclose(fp);
-       return 1;
+       return stale;
 }
 
 static int compare_info(const void *a_, const void *b_)
@@ -194,28 +284,21 @@ static void init_pack_info(const char *infofile, int force)
 {
        struct packed_git *p;
        int stale;
-       int i = 0;
-
-       objdir = get_object_directory();
-       objdirlen = strlen(objdir);
+       int i;
+       size_t alloc = 0;
 
        for (p = get_all_packs(the_repository); p; p = p->next) {
                /* we ignore things on alternate path since they are
                 * not available to the pullers in general.
                 */
-               if (!p->pack_local)
-                       continue;
-               i++;
-       }
-       num_pack = i;
-       info = xcalloc(num_pack, sizeof(struct pack_info *));
-       for (i = 0, p = get_all_packs(the_repository); p; p = p->next) {
-               if (!p->pack_local)
+               if (!p->pack_local || !file_exists(p->pack_name))
                        continue;
+
+               i = num_pack++;
+               ALLOC_GROW(info, num_pack, alloc);
                info[i] = xcalloc(1, sizeof(struct pack_info));
                info[i]->p = p;
                info[i]->old_num = -1;
-               i++;
        }
 
        if (infofile && !force)
@@ -241,14 +324,14 @@ static void free_pack_info(void)
        free(info);
 }
 
-static int write_pack_info_file(FILE *fp)
+static int write_pack_info_file(struct update_info_ctx *uic)
 {
        int i;
        for (i = 0; i < num_pack; i++) {
-               if (fprintf(fp, "P %s\n", info[i]->p->pack_name + objdirlen + 6) < 0)
+               if (uic_printf(uic, "P %s\n", pack_basename(info[i]->p)) < 0)
                        return -1;
        }
-       if (fputc('\n', fp) == EOF)
+       if (uic_printf(uic, "\n") < 0)
                return -1;
        return 0;
 }
@@ -259,7 +342,7 @@ static int update_info_packs(int force)
        int ret;
 
        init_pack_info(infofile, force);
-       ret = update_info_file(infofile, write_pack_info_file);
+       ret = update_info_file(infofile, write_pack_info_file, force);
        free_pack_info();
        free(infofile);
        return ret;