builtin/hash-object.c

   1 /*
   2  * GIT - The information manager from hell
   3  *
   4  * Copyright (C) Linus Torvalds, 2005
   5  * Copyright (C) Junio C Hamano, 2005
   6  */
   7 #include "builtin.h"
   8 #include "abspath.h"
   9 #include "config.h"
  10 #include "gettext.h"
  11 #include "hex.h"
  12 #include "object-file.h"
  13 #include "object-store-ll.h"
  14 #include "blob.h"
  15 #include "quote.h"
  16 #include "parse-options.h"
  17 #include "setup.h"
  18 #include "strbuf.h"
  19 #include "write-or-die.h"
  20
  21 /*
  22  * This is to create corrupt objects for debugging and as such it
  23  * needs to bypass the data conversion performed by, and the type
  24  * limitation imposed by, index_fd() and its callees.
  25  */
  26 static int hash_literally(struct object_id *oid, int fd, const char *type, unsigned flags)
  27 {
  28         struct strbuf buf = STRBUF_INIT;
  29         int ret;
  30
  31         if (strbuf_read(&buf, fd, 4096) < 0)
  32                 ret = -1;
  33         else
  34                 ret = write_object_file_literally(buf.buf, buf.len, type, oid,
  35                                                  flags);
  36         close(fd);
  37         strbuf_release(&buf);
  38         return ret;
  39 }
  40
  41 static void hash_fd(int fd, const char *type, const char *path, unsigned flags,
  42                     int literally)
  43 {
  44         struct stat st;
  45         struct object_id oid;
  46
  47         if (fstat(fd, &st) < 0 ||
  48             (literally
  49              ? hash_literally(&oid, fd, type, flags)
  50              : index_fd(the_repository->index, &oid, fd, &st,
  51                         type_from_string(type), path, flags)))
  52                 die((flags & HASH_WRITE_OBJECT)
  53                     ? "Unable to add %s to database"
  54                     : "Unable to hash %s", path);
  55         printf("%s\n", oid_to_hex(&oid));
  56         maybe_flush_or_die(stdout, "hash to stdout");
  57 }
  58
  59 static void hash_object(const char *path, const char *type, const char *vpath,
  60                         unsigned flags, int literally)
  61 {
  62         int fd;
  63         fd = xopen(path, O_RDONLY);
  64         hash_fd(fd, type, vpath, flags, literally);
  65 }
  66
  67 static void hash_stdin_paths(const char *type, int no_filters, unsigned flags,
  68                              int literally)
  69 {
  70         struct strbuf buf = STRBUF_INIT;
  71         struct strbuf unquoted = STRBUF_INIT;
  72
  73         while (strbuf_getline(&buf, stdin) != EOF) {
  74                 if (buf.buf[0] == '"') {
  75                         strbuf_reset(&unquoted);
  76                         if (unquote_c_style(&unquoted, buf.buf, NULL))
  77                                 die("line is badly quoted");
  78                         strbuf_swap(&buf, &unquoted);
  79                 }
  80                 hash_object(buf.buf, type, no_filters ? NULL : buf.buf, flags,
  81                             literally);
  82         }
  83         strbuf_release(&buf);
  84         strbuf_release(&unquoted);
  85 }
  86
  87 int cmd_hash_object(int argc, const char **argv, const char *prefix)
  88 {
  89         static const char * const hash_object_usage[] = {
  90                 N_("git hash-object [-t <type>] [-w] [--path=<file> | --no-filters]\n"
  91                    "                [--stdin [--literally]] [--] <file>..."),
  92                 N_("git hash-object [-t <type>] [-w] --stdin-paths [--no-filters]"),
  93                 NULL
  94         };
  95         const char *type = blob_type;
  96         int hashstdin = 0;
  97         int stdin_paths = 0;
  98         int no_filters = 0;
  99         int literally = 0;
 100         int nongit = 0;
 101         unsigned flags = HASH_FORMAT_CHECK;
 102         const char *vpath = NULL;
 103         char *vpath_free = NULL;
 104         const struct option hash_object_options[] = {
 105                 OPT_STRING('t', NULL, &type, N_("type"), N_("object type")),
 106                 OPT_BIT('w', NULL, &flags, N_("write the object into the object database"),
 107                         HASH_WRITE_OBJECT),
 108                 OPT_COUNTUP( 0 , "stdin", &hashstdin, N_("read the object from stdin")),
 109                 OPT_BOOL( 0 , "stdin-paths", &stdin_paths, N_("read file names from stdin")),
 110                 OPT_BOOL( 0 , "no-filters", &no_filters, N_("store file as is without filters")),
 111                 OPT_BOOL( 0, "literally", &literally, N_("just hash any random garbage to create corrupt objects for debugging Git")),
 112                 OPT_STRING( 0 , "path", &vpath, N_("file"), N_("process file as it were from this path")),
 113                 OPT_END()
 114         };
 115         int i;
 116         const char *errstr = NULL;
 117
 118         argc = parse_options(argc, argv, prefix, hash_object_options,
 119                              hash_object_usage, 0);
 120
 121         if (flags & HASH_WRITE_OBJECT)
 122                 prefix = setup_git_directory();
 123         else
 124                 prefix = setup_git_directory_gently(&nongit);
 125
 126         if (nongit && !the_hash_algo)
 127                 repo_set_hash_algo(the_repository, GIT_HASH_SHA1);
 128
 129         if (vpath && prefix) {
 130                 vpath_free = prefix_filename(prefix, vpath);
 131                 vpath = vpath_free;
 132         }
 133
 134         git_config(git_default_config, NULL);
 135
 136         if (stdin_paths) {
 137                 if (hashstdin)
 138                         errstr = "Can't use --stdin-paths with --stdin";
 139                 else if (argc)
 140                         errstr = "Can't specify files with --stdin-paths";
 141                 else if (vpath)
 142                         errstr = "Can't use --stdin-paths with --path";
 143         }
 144         else {
 145                 if (hashstdin > 1)
 146                         errstr = "Multiple --stdin arguments are not supported";
 147                 if (vpath && no_filters)
 148                         errstr = "Can't use --path with --no-filters";
 149         }
 150
 151         if (errstr) {
 152                 error("%s", errstr);
 153                 usage_with_options(hash_object_usage, hash_object_options);
 154         }
 155
 156         if (hashstdin)
 157                 hash_fd(0, type, vpath, flags, literally);
 158
 159         for (i = 0 ; i < argc; i++) {
 160                 const char *arg = argv[i];
 161                 char *to_free = NULL;
 162
 163                 if (prefix)
 164                         arg = to_free = prefix_filename(prefix, arg);
 165                 hash_object(arg, type, no_filters ? NULL : vpath ? vpath : arg,
 166                             flags, literally);
 167                 free(to_free);
 168         }
 169
 170         if (stdin_paths)
 171                 hash_stdin_paths(type, no_filters, flags, literally);
 172
 173         free(vpath_free);
 174
 175         return 0;
 176 }