builtin/checkout--worker.c

   1 #include "builtin.h"
   2 #include "alloc.h"
   3 #include "config.h"
   4 #include "entry.h"
   5 #include "gettext.h"
   6 #include "parallel-checkout.h"
   7 #include "parse-options.h"
   8 #include "pkt-line.h"
   9 #include "read-cache-ll.h"
  10
  11 static void packet_to_pc_item(const char *buffer, int len,
  12                               struct parallel_checkout_item *pc_item)
  13 {
  14         const struct pc_item_fixed_portion *fixed_portion;
  15         const char *variant;
  16         char *encoding;
  17
  18         if (len < sizeof(struct pc_item_fixed_portion))
  19                 BUG("checkout worker received too short item (got %dB, exp %dB)",
  20                     len, (int)sizeof(struct pc_item_fixed_portion));
  21
  22         fixed_portion = (struct pc_item_fixed_portion *)buffer;
  23
  24         if (len - sizeof(struct pc_item_fixed_portion) !=
  25                 fixed_portion->name_len + fixed_portion->working_tree_encoding_len)
  26                 BUG("checkout worker received corrupted item");
  27
  28         variant = buffer + sizeof(struct pc_item_fixed_portion);
  29
  30         /*
  31          * Note: the main process uses zero length to communicate that the
  32          * encoding is NULL. There is no use case that requires sending an
  33          * actual empty string, since convert_attrs() never sets
  34          * ca.working_tree_enconding to "".
  35          */
  36         if (fixed_portion->working_tree_encoding_len) {
  37                 encoding = xmemdupz(variant,
  38                                     fixed_portion->working_tree_encoding_len);
  39                 variant += fixed_portion->working_tree_encoding_len;
  40         } else {
  41                 encoding = NULL;
  42         }
  43
  44         memset(pc_item, 0, sizeof(*pc_item));
  45         pc_item->ce = make_empty_transient_cache_entry(fixed_portion->name_len, NULL);
  46         pc_item->ce->ce_namelen = fixed_portion->name_len;
  47         pc_item->ce->ce_mode = fixed_portion->ce_mode;
  48         memcpy(pc_item->ce->name, variant, pc_item->ce->ce_namelen);
  49         oidcpy(&pc_item->ce->oid, &fixed_portion->oid);
  50
  51         pc_item->id = fixed_portion->id;
  52         pc_item->ca.crlf_action = fixed_portion->crlf_action;
  53         pc_item->ca.ident = fixed_portion->ident;
  54         pc_item->ca.working_tree_encoding = encoding;
  55 }
  56
  57 static void report_result(struct parallel_checkout_item *pc_item)
  58 {
  59         struct pc_item_result res = { 0 };
  60         size_t size;
  61
  62         res.id = pc_item->id;
  63         res.status = pc_item->status;
  64
  65         if (pc_item->status == PC_ITEM_WRITTEN) {
  66                 res.st = pc_item->st;
  67                 size = sizeof(res);
  68         } else {
  69                 size = PC_ITEM_RESULT_BASE_SIZE;
  70         }
  71
  72         packet_write(1, (const char *)&res, size);
  73 }
  74
  75 /* Free the worker-side malloced data, but not pc_item itself. */
  76 static void release_pc_item_data(struct parallel_checkout_item *pc_item)
  77 {
  78         free((char *)pc_item->ca.working_tree_encoding);
  79         discard_cache_entry(pc_item->ce);
  80 }
  81
  82 static void worker_loop(struct checkout *state)
  83 {
  84         struct parallel_checkout_item *items = NULL;
  85         size_t i, nr = 0, alloc = 0;
  86
  87         while (1) {
  88                 int len = packet_read(0, packet_buffer, sizeof(packet_buffer),
  89                                       0);
  90
  91                 if (len < 0)
  92                         BUG("packet_read() returned negative value");
  93                 else if (!len)
  94                         break;
  95
  96                 ALLOC_GROW(items, nr + 1, alloc);
  97                 packet_to_pc_item(packet_buffer, len, &items[nr++]);
  98         }
  99
 100         for (i = 0; i < nr; i++) {
 101                 struct parallel_checkout_item *pc_item = &items[i];
 102                 write_pc_item(pc_item, state);
 103                 report_result(pc_item);
 104                 release_pc_item_data(pc_item);
 105         }
 106
 107         packet_flush(1);
 108
 109         free(items);
 110 }
 111
 112 static const char * const checkout_worker_usage[] = {
 113         N_("git checkout--worker [<options>]"),
 114         NULL
 115 };
 116
 117 int cmd_checkout__worker(int argc, const char **argv, const char *prefix)
 118 {
 119         struct checkout state = CHECKOUT_INIT;
 120         struct option checkout_worker_options[] = {
 121                 OPT_STRING(0, "prefix", &state.base_dir, N_("string"),
 122                         N_("when creating files, prepend <string>")),
 123                 OPT_END()
 124         };
 125
 126         if (argc == 2 && !strcmp(argv[1], "-h"))
 127                 usage_with_options(checkout_worker_usage,
 128                                    checkout_worker_options);
 129
 130         git_config(git_default_config, NULL);
 131         argc = parse_options(argc, argv, prefix, checkout_worker_options,
 132                              checkout_worker_usage, 0);
 133         if (argc > 0)
 134                 usage_with_options(checkout_worker_usage, checkout_worker_options);
 135
 136         if (state.base_dir)
 137                 state.base_dir_len = strlen(state.base_dir);
 138
 139         /*
 140          * Setting this on a worker won't actually update the index. We just
 141          * need to tell the checkout machinery to lstat() the written entries,
 142          * so that we can send this data back to the main process.
 143          */
 144         state.refresh_cache = 1;
 145
 146         worker_loop(&state);
 147         return 0;
 148 }