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