ui-snapshot.c

   1 /* ui-snapshot.c: generate snapshot of a commit
   2  *
   3  * Copyright (C) 2006 Lars Hjemli
   4  *
   5  * Licensed under GNU General Public License v2
   6  *   (see COPYING for full license text)
   7  */
   8
   9 #include "cgit.h"
  10 #include "html.h"
  11 #include "ui-shared.h"
  12
  13 static int write_compressed_tar_archive(struct archiver_args *args,const char *filter)
  14 {
  15         int rw[2];
  16         pid_t gzpid;
  17         int stdout2;
  18         int status;
  19         int rv;
  20
  21         stdout2 = chk_non_negative(dup(STDIN_FILENO), "Preserving STDOUT before compressing");
  22         chk_zero(pipe(rw), "Opening pipe from compressor subprocess");
  23         gzpid = chk_non_negative(fork(), "Forking compressor subprocess");
  24         if(gzpid==0) {
  25                 /* child */
  26                 chk_zero(close(rw[1]), "Closing write end of pipe in child");
  27                 chk_zero(close(STDIN_FILENO), "Closing STDIN");
  28                 chk_non_negative(dup2(rw[0],STDIN_FILENO), "Redirecting compressor input to stdin");
  29                 execlp(filter,filter,NULL);
  30                 _exit(-1);
  31         }
  32         /* parent */
  33         chk_zero(close(rw[0]), "Closing read end of pipe");
  34         chk_non_negative(dup2(rw[1],STDOUT_FILENO), "Redirecting output to compressor");
  35
  36         rv = write_tar_archive(args);
  37
  38         chk_zero(close(STDOUT_FILENO), "Closing STDOUT redirected to compressor");
  39         chk_non_negative(dup2(stdout2,STDOUT_FILENO), "Restoring uncompressed STDOUT");
  40         chk_zero(close(stdout2), "Closing uncompressed STDOUT");
  41         chk_zero(close(rw[1]), "Closing write end of pipe in parent");
  42         chk_positive(waitpid(gzpid,&status,0), "Waiting on compressor process");
  43         if(! ( WIFEXITED(status) && WEXITSTATUS(status)==0 ) )
  44                 cgit_print_error("Failed to compress archive");
  45
  46         return rv;
  47 }
  48
  49 static int write_tar_gzip_archive(struct archiver_args *args)
  50 {
  51         return write_compressed_tar_archive(args,"gzip");
  52 }
  53
  54 static int write_tar_bzip2_archive(struct archiver_args *args)
  55 {
  56         return write_compressed_tar_archive(args,"bzip2");
  57 }
  58
  59 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
  60         { ".zip", "application/x-zip", write_zip_archive, 0x1 },
  61         { ".tar.gz", "application/x-gzip", write_tar_gzip_archive, 0x2 },
  62         { ".tar.bz2", "application/x-bzip2", write_tar_bzip2_archive, 0x4 },
  63         { ".tar", "application/x-tar", write_tar_archive, 0x8 },
  64         {}
  65 };
  66
  67 static const struct cgit_snapshot_format *get_format(const char *filename)
  68 {
  69         const struct cgit_snapshot_format *fmt;
  70         int fl, sl;
  71
  72         fl = strlen(filename);
  73         for(fmt = cgit_snapshot_formats; fmt->suffix; fmt++) {
  74                 sl = strlen(fmt->suffix);
  75                 if (sl >= fl)
  76                         continue;
  77                 if (!strcmp(fmt->suffix, filename + fl - sl))
  78                         return fmt;
  79         }
  80         return NULL;
  81 }
  82
  83 static int make_snapshot(const struct cgit_snapshot_format *format,
  84                          const char *hex, const char *prefix,
  85                          const char *filename)
  86 {
  87         struct archiver_args args;
  88         struct commit *commit;
  89         unsigned char sha1[20];
  90
  91         if(get_sha1(hex, sha1)) {
  92                 cgit_print_error(fmt("Bad object id: %s", hex));
  93                 return 1;
  94         }
  95         commit = lookup_commit_reference(sha1);
  96         if(!commit) {
  97                 cgit_print_error(fmt("Not a commit reference: %s", hex));
  98                 return 1;
  99         }
 100         memset(&args, 0, sizeof(args));
 101         if (prefix) {
 102                 args.base = fmt("%s/", prefix);
 103                 args.baselen = strlen(prefix) + 1;
 104         } else {
 105                 args.base = "";
 106                 args.baselen = 0;
 107         }
 108         args.tree = commit->tree;
 109         args.time = commit->date;
 110         ctx.page.mimetype = xstrdup(format->mimetype);
 111         ctx.page.filename = xstrdup(filename);
 112         cgit_print_http_headers(&ctx);
 113         format->write_func(&args);
 114         return 0;
 115 }
 116
 117 /* Try to guess the requested revision from the requested snapshot name.
 118  * First the format extension is stripped, e.g. "cgit-0.7.2.tar.gz" become
 119  * "cgit-0.7.2". If this is a valid commit object name we've got a winner.
 120  * Otherwise, if the snapshot name has a prefix matching the result from
 121  * repo_basename(), we strip the basename and any following '-' and '_'
 122  * characters ("cgit-0.7.2" -> "0.7.2") and check the resulting name once
 123  * more. If this still isn't a valid commit object name, we check if pre-
 124  * pending a 'v' to the remaining snapshot name ("0.7.2" -> "v0.7.2") gives
 125  * us something valid.
 126  */
 127 static const char *get_ref_from_filename(const char *url, const char *filename,
 128                                          const struct cgit_snapshot_format *format)
 129 {
 130         const char *reponame;
 131         unsigned char sha1[20];
 132         char *snapshot;
 133
 134         snapshot = xstrdup(filename);
 135         snapshot[strlen(snapshot) - strlen(format->suffix)] = '\0';
 136         fprintf(stderr, "snapshot=%s\n", snapshot);
 137
 138         if (get_sha1(snapshot, sha1) == 0)
 139                 return snapshot;
 140
 141         reponame = cgit_repobasename(url);
 142         fprintf(stderr, "reponame=%s\n", reponame);
 143         if (prefixcmp(snapshot, reponame) == 0) {
 144                 snapshot += strlen(reponame);
 145                 while (snapshot && (*snapshot == '-' || *snapshot == '_'))
 146                         snapshot++;
 147         }
 148
 149         if (get_sha1(snapshot, sha1) == 0)
 150                 return snapshot;
 151
 152         snapshot = fmt("v%s", snapshot);
 153         if (get_sha1(snapshot, sha1) == 0)
 154                 return snapshot;
 155
 156         return NULL;
 157 }
 158
 159 void cgit_print_snapshot(const char *head, const char *hex,
 160                          const char *filename, int snapshots, int dwim)
 161 {
 162         const struct cgit_snapshot_format* f;
 163         char *prefix = NULL;
 164
 165         f = get_format(filename);
 166         if (!f) {
 167                 ctx.page.mimetype = "text/html";
 168                 cgit_print_http_headers(&ctx);
 169                 cgit_print_docstart(&ctx);
 170                 cgit_print_pageheader(&ctx);
 171                 cgit_print_error(fmt("Unsupported snapshot format: %s", filename));
 172                 cgit_print_docend();
 173                 return;
 174         }
 175
 176         if (!hex && dwim) {
 177                 hex = get_ref_from_filename(ctx.repo->url, filename, f);
 178                 if (hex == NULL) {
 179                         html_status(404, "Not found", 0);
 180                         return;
 181                 }
 182                 prefix = xstrdup(filename);
 183                 prefix[strlen(filename) - strlen(f->suffix)] = '\0';
 184         }
 185
 186         if (!hex)
 187                 hex = head;
 188
 189         if (!prefix)
 190                 prefix = xstrdup(cgit_repobasename(ctx.repo->url));
 191
 192         make_snapshot(f, hex, prefix, filename);
 193         free(prefix);
 194 }