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