fsmonitor-ipc.c

   1 #include "cache.h"
   2 #include "fsmonitor.h"
   3 #include "gettext.h"
   4 #include "simple-ipc.h"
   5 #include "fsmonitor-ipc.h"
   6 #include "repository.h"
   7 #include "run-command.h"
   8 #include "strbuf.h"
   9 #include "trace2.h"
  10
  11 #ifndef HAVE_FSMONITOR_DAEMON_BACKEND
  12
  13 /*
  14  * A trivial implementation of the fsmonitor_ipc__ API for unsupported
  15  * platforms.
  16  */
  17
  18 int fsmonitor_ipc__is_supported(void)
  19 {
  20         return 0;
  21 }
  22
  23 const char *fsmonitor_ipc__get_path(struct repository *r)
  24 {
  25         return NULL;
  26 }
  27
  28 enum ipc_active_state fsmonitor_ipc__get_state(void)
  29 {
  30         return IPC_STATE__OTHER_ERROR;
  31 }
  32
  33 int fsmonitor_ipc__send_query(const char *since_token,
  34                               struct strbuf *answer)
  35 {
  36         return -1;
  37 }
  38
  39 int fsmonitor_ipc__send_command(const char *command,
  40                                 struct strbuf *answer)
  41 {
  42         return -1;
  43 }
  44
  45 #else
  46
  47 int fsmonitor_ipc__is_supported(void)
  48 {
  49         return 1;
  50 }
  51
  52 enum ipc_active_state fsmonitor_ipc__get_state(void)
  53 {
  54         return ipc_get_active_state(fsmonitor_ipc__get_path(the_repository));
  55 }
  56
  57 static int spawn_daemon(void)
  58 {
  59         struct child_process cmd = CHILD_PROCESS_INIT;
  60
  61         cmd.git_cmd = 1;
  62         cmd.no_stdin = 1;
  63         cmd.trace2_child_class = "fsmonitor";
  64         strvec_pushl(&cmd.args, "fsmonitor--daemon", "start", NULL);
  65
  66         return run_command(&cmd);
  67 }
  68
  69 int fsmonitor_ipc__send_query(const char *since_token,
  70                               struct strbuf *answer)
  71 {
  72         int ret = -1;
  73         int tried_to_spawn = 0;
  74         enum ipc_active_state state = IPC_STATE__OTHER_ERROR;
  75         struct ipc_client_connection *connection = NULL;
  76         struct ipc_client_connect_options options
  77                 = IPC_CLIENT_CONNECT_OPTIONS_INIT;
  78         const char *tok = since_token ? since_token : "";
  79         size_t tok_len = since_token ? strlen(since_token) : 0;
  80
  81         options.wait_if_busy = 1;
  82         options.wait_if_not_found = 0;
  83
  84         trace2_region_enter("fsm_client", "query", NULL);
  85         trace2_data_string("fsm_client", NULL, "query/command", tok);
  86
  87 try_again:
  88         state = ipc_client_try_connect(fsmonitor_ipc__get_path(the_repository),
  89                                                 &options, &connection);
  90
  91         switch (state) {
  92         case IPC_STATE__LISTENING:
  93                 ret = ipc_client_send_command_to_connection(
  94                         connection, tok, tok_len, answer);
  95                 ipc_client_close_connection(connection);
  96
  97                 trace2_data_intmax("fsm_client", NULL,
  98                                    "query/response-length", answer->len);
  99                 goto done;
 100
 101         case IPC_STATE__NOT_LISTENING:
 102         case IPC_STATE__PATH_NOT_FOUND:
 103                 if (tried_to_spawn)
 104                         goto done;
 105
 106                 tried_to_spawn++;
 107                 if (spawn_daemon())
 108                         goto done;
 109
 110                 /*
 111                  * Try again, but this time give the daemon a chance to
 112                  * actually create the pipe/socket.
 113                  *
 114                  * Granted, the daemon just started so it can't possibly have
 115                  * any FS cached yet, so we'll always get a trivial answer.
 116                  * BUT the answer should include a new token that can serve
 117                  * as the basis for subsequent requests.
 118                  */
 119                 options.wait_if_not_found = 1;
 120                 goto try_again;
 121
 122         case IPC_STATE__INVALID_PATH:
 123                 ret = error(_("fsmonitor_ipc__send_query: invalid path '%s'"),
 124                             fsmonitor_ipc__get_path(the_repository));
 125                 goto done;
 126
 127         case IPC_STATE__OTHER_ERROR:
 128         default:
 129                 ret = error(_("fsmonitor_ipc__send_query: unspecified error on '%s'"),
 130                             fsmonitor_ipc__get_path(the_repository));
 131                 goto done;
 132         }
 133
 134 done:
 135         trace2_region_leave("fsm_client", "query", NULL);
 136
 137         return ret;
 138 }
 139
 140 int fsmonitor_ipc__send_command(const char *command,
 141                                 struct strbuf *answer)
 142 {
 143         struct ipc_client_connection *connection = NULL;
 144         struct ipc_client_connect_options options
 145                 = IPC_CLIENT_CONNECT_OPTIONS_INIT;
 146         int ret;
 147         enum ipc_active_state state;
 148         const char *c = command ? command : "";
 149         size_t c_len = command ? strlen(command) : 0;
 150
 151         strbuf_reset(answer);
 152
 153         options.wait_if_busy = 1;
 154         options.wait_if_not_found = 0;
 155
 156         state = ipc_client_try_connect(fsmonitor_ipc__get_path(the_repository),
 157                                                 &options, &connection);
 158         if (state != IPC_STATE__LISTENING) {
 159                 die(_("fsmonitor--daemon is not running"));
 160                 return -1;
 161         }
 162
 163         ret = ipc_client_send_command_to_connection(connection, c, c_len,
 164                                                     answer);
 165         ipc_client_close_connection(connection);
 166
 167         if (ret == -1) {
 168                 die(_("could not send '%s' command to fsmonitor--daemon"), c);
 169                 return -1;
 170         }
 171
 172         return 0;
 173 }
 174
 175 #endif