write-tree.con commit Update tutorial for simplified "git" script. (81bb573)
   1/*
   2 * GIT - The information manager from hell
   3 *
   4 * Copyright (C) Linus Torvalds, 2005
   5 */
   6#include "cache.h"
   7
   8static int check_valid_sha1(unsigned char *sha1)
   9{
  10        char *filename = sha1_file_name(sha1);
  11        int ret;
  12
  13        /* If we were anal, we'd check that the sha1 of the contents actually matches */
  14        ret = access(filename, R_OK);
  15        if (ret)
  16                perror(filename);
  17        return ret;
  18}
  19
  20static int write_tree(struct cache_entry **cachep, int maxentries, const char *base, int baselen, unsigned char *returnsha1)
  21{
  22        unsigned char subdir_sha1[20];
  23        unsigned long size, offset;
  24        char *buffer;
  25        int nr;
  26
  27        /* Guess at some random initial size */
  28        size = 8192;
  29        buffer = xmalloc(size);
  30        offset = 0;
  31
  32        nr = 0;
  33        while (nr < maxentries) {
  34                struct cache_entry *ce = cachep[nr];
  35                const char *pathname = ce->name, *filename, *dirname;
  36                int pathlen = ce_namelen(ce), entrylen;
  37                unsigned char *sha1;
  38                unsigned int mode;
  39
  40                /* Did we hit the end of the directory? Return how many we wrote */
  41                if (baselen >= pathlen || memcmp(base, pathname, baselen))
  42                        break;
  43
  44                sha1 = ce->sha1;
  45                mode = ntohl(ce->ce_mode);
  46
  47                /* Do we have _further_ subdirectories? */
  48                filename = pathname + baselen;
  49                dirname = strchr(filename, '/');
  50                if (dirname) {
  51                        int subdir_written;
  52
  53                        subdir_written = write_tree(cachep + nr, maxentries - nr, pathname, dirname-pathname+1, subdir_sha1);
  54                        nr += subdir_written;
  55
  56                        /* Now we need to write out the directory entry into this tree.. */
  57                        mode = S_IFDIR;
  58                        pathlen = dirname - pathname;
  59
  60                        /* ..but the directory entry doesn't count towards the total count */
  61                        nr--;
  62                        sha1 = subdir_sha1;
  63                }
  64
  65                if (check_valid_sha1(sha1) < 0)
  66                        exit(1);
  67
  68                entrylen = pathlen - baselen;
  69                if (offset + entrylen + 100 > size) {
  70                        size = alloc_nr(offset + entrylen + 100);
  71                        buffer = xrealloc(buffer, size);
  72                }
  73                offset += sprintf(buffer + offset, "%o %.*s", mode, entrylen, filename);
  74                buffer[offset++] = 0;
  75                memcpy(buffer + offset, sha1, 20);
  76                offset += 20;
  77                nr++;
  78        }
  79
  80        write_sha1_file(buffer, offset, "tree", returnsha1);
  81        free(buffer);
  82        return nr;
  83}
  84
  85int main(int argc, char **argv)
  86{
  87        int i, funny;
  88        int entries = read_cache();
  89        unsigned char sha1[20];
  90
  91        if (entries < 0)
  92                die("git-write-tree: error reading cache");
  93
  94        /* Verify that the tree is merged */
  95        funny = 0;
  96        for (i = 0; i < entries; i++) {
  97                struct cache_entry *ce = active_cache[i];
  98                if (ntohs(ce->ce_flags) & ~CE_NAMEMASK) {
  99                        if (10 < ++funny) {
 100                                fprintf(stderr, "...\n");
 101                                break;
 102                        }
 103                        fprintf(stderr, "%s: unmerged (%s)\n", ce->name, sha1_to_hex(ce->sha1));
 104                }
 105        }
 106        if (funny)
 107                die("git-write-tree: not able to write tree");
 108
 109        /* Also verify that the cache does not have path and path/file
 110         * at the same time.  At this point we know the cache has only
 111         * stage 0 entries.
 112         */
 113        funny = 0;
 114        for (i = 0; i < entries - 1; i++) {
 115                /* path/file always comes after path because of the way
 116                 * the cache is sorted.  Also path can appear only once,
 117                 * which means conflicting one would immediately follow.
 118                 */
 119                const char *this_name = active_cache[i]->name;
 120                const char *next_name = active_cache[i+1]->name;
 121                int this_len = strlen(this_name);
 122                if (this_len < strlen(next_name) &&
 123                    strncmp(this_name, next_name, this_len) == 0 &&
 124                    next_name[this_len] == '/') {
 125                        if (10 < ++funny) {
 126                                fprintf(stderr, "...\n");
 127                                break;
 128                        }
 129                        fprintf(stderr, "You have both %s and %s\n",
 130                                this_name, next_name);
 131                }
 132        }
 133        if (funny)
 134                die("git-write-tree: not able to write tree");
 135
 136        /* Ok, write it out */
 137        if (write_tree(active_cache, entries, "", 0, sha1) != entries)
 138                die("git-write-tree: internal error");
 139        printf("%s\n", sha1_to_hex(sha1));
 140        return 0;
 141}