fsmonitor-ipc.c

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