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