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 
packet_to_pc_item(const char * buffer,int len,struct parallel_checkout_item * pc_item)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 
report_result(struct parallel_checkout_item * pc_item)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. */
release_pc_item_data(struct parallel_checkout_item * pc_item)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 
worker_loop(struct checkout * state)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 
cmd_checkout__worker(int argc,const char ** argv,const char * prefix)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 }
146