builtin/checkout--worker.c

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