[watchman] jsonify protocol

Summary:
fix the protocol handling by adopting json for both the requests and
the response.

This also allows us to remove the dependency on libevent (which is honestly a
bit of a cluster... to handle portably), so now all our dependencies are either
in the base system or are included in our source code.

This depends on D645447 for the integration test pieces.

We always return a JSON object response that includes our version number.
Errors will always have an "error" object field that holds the text of the
error.  The rest of the commands are still transitional when it comes to their
response format, but I'll be updating the README as I review/revise each of
those.

I've pulled in version 2.4 of the Jansson JSON library, which is compatibly MIT
licensed.  Doc on it can be found here: http://www.digip.org/jansson/doc/2.4/

Test Plan: `make integration`

Reviewers: jakubv, keegancsmith, zoel

CC: pieter, fugalh, security-diffs@lists

Differential Revision: https://phabricator.fb.com/D645534

.gitignore

@@ -16,7 +16,9 @@ arcanist/.phutil_module_cache
 *.swp
 compile
 stamp-h1
-watchman-config.h
+config.h
+thirdparty/jansson/jansson_config.h
 compile
 tests/*.t
 .dirstamp
+*.a

Makefile.am

@@ -1,5 +1,9 @@
 bin_PROGRAMS = watchman
 
+THIRDPARTY_CPPFLAGS = -Ithirdparty/jansson
+
+watchman_CPPFLAGS = $(THIRDPARTY_CPPFLAGS)
+watchman_LDADD = -L. -lwmanjson
 watchman_SOURCES = \
 	argv.c       \
 	hash.c       \
@@ -13,6 +17,26 @@ noinst_HEADERS =   \
 	watchman.h       \
 	watchman_hash.h
 
+noinst_LIBRARIES = libwmanjson.a
+
+# bundled json library
+libwmanjson_a_CPPFLAGS = $(THIRDPARTY_CPPFLAGS)
+libwmanjson_a_SOURCES = \
+	thirdparty/jansson/dump.c \
+	thirdparty/jansson/error.c \
+	thirdparty/jansson/hashtable.c \
+	thirdparty/jansson/hashtable.h \
+	thirdparty/jansson/jansson_private.h \
+	thirdparty/jansson/load.c \
+	thirdparty/jansson/memory.c \
+	thirdparty/jansson/pack_unpack.c \
+	thirdparty/jansson/strbuffer.c \
+	thirdparty/jansson/strbuffer.h \
+	thirdparty/jansson/strconv.c \
+	thirdparty/jansson/utf.c \
+	thirdparty/jansson/utf.h \
+	thirdparty/jansson/value.c
+
 # unit tests
 TESTS = tests/argv.t
 noinst_PROGRAMS = tests/argv.t
@@ -25,6 +49,7 @@ build-tests: $(TESTS)
 integration:
 	arc unit --engine WatchmanIntegrationEngine
 
+tests_argv_t_CPPFLAGS = $(THIRDPARTY_CPPFLAGS)
 tests_argv_t_SOURCES = \
 	thirdparty/tap.c  \
 	tests/argv.c \

arcanist/lib/WatchmanInstance.php

@@ -23,6 +23,7 @@ class WatchmanInstance {
   private $dir;
   private $invocations = 0;
   private $debug = false;
+  private $sock;
 
   function __construct() {
     $this->dir = PhutilDirectoryFixture::newEmptyFixture();
@@ -43,6 +44,27 @@ function command() {
     return newv('ExecFuture', $args);
   }
 
+  function request() {
+    $args = func_get_args();
+
+    if (!$this->invocations) {
+      return call_user_func_array(
+        array($this, 'resolveCommand'),
+        $args);
+    }
+
+    // Use a socket instead
+    if (!$this->sock) {
+      $this->sock = fsockopen('unix://' .
+        $this->dir->getPath() . '/.watchman.' .
+        getenv('USER'));
+    }
+
+    fwrite($this->sock, json_encode($args));
+    $data = fgets($this->sock);
+    return json_decode($data, true);
+  }
+
   function resolveCommand() {
     $args = func_get_args();
 
@@ -53,9 +75,7 @@ function resolveCommand() {
     if ($this->debug) {
       echo "running: " . $future->getCommand() . "\n";
     }
-    list($out) = $future->resolvex();
-
-    return $out;
+    return $future->resolveJSON();
   }
 
   function __destruct() {

arcanist/lib/WatchmanTestCase.php

@@ -39,7 +39,7 @@ function watchmanCommand() {
     }
 
     return call_user_func_array(
-      array($this->watchman, 'resolveCommand'),
+      array($this->watchman, 'request'),
       $args);
   }
 

configure.ac

@@ -1,27 +1,28 @@
 AC_INIT([watchman], [1.0], [], [watchman])
-AM_INIT_AUTOMAKE([dist-bzip2 subdir-objects -Wall])
+AM_INIT_AUTOMAKE([dist-bzip2 subdir-objects])
 AC_PROG_CC
 AC_C_BIGENDIAN
+AC_C_INLINE
+AC_PROG_RANLIB
 
 AM_PROG_CC_C_O
 AM_PROG_AS
 
-AC_SEARCH_LIBS(
-  [event_init],
-  [event event-1.4 event2],
-  [found_libevent=yes],
-  [found_libevent=no]
-)
+dnl could do some feature testing here to turn on a safe set
+dnl of warnings, and also add an option to turn on -Werror
+dnl for maintainers.
+if test -n "$GCC" ; then
+  CFLAGS="$CFLAGS -Wall -Wextra -Wdeclaration-after-statement"
+  dnl -Werror
+fi
 
-AC_CHECK_HEADERS(event.h sys/inotify.h sys/event.h)
+AC_SEARCH_LIBS([pthread_create], [pthread])
 
-AC_CHECK_FUNCS(kqueue inotify_init)
+AC_CHECK_HEADERS(locale.h sys/inotify.h sys/event.h)
+AC_CHECK_FUNCS(kqueue inotify_init strtoll localeconv)
 
-if test "x$found_libevent" = "xno" ; then
-  AC_MSG_ERROR("we need libevent")
-fi
-AC_CONFIG_HEADER([watchman-config.h])
-AC_CONFIG_FILES([Makefile])
+AC_CONFIG_HEADER([config.h])
+AC_CONFIG_FILES([Makefile thirdparty/jansson/jansson_config.h])
 AC_OUTPUT
 
 dnl vim:ts=2:sw=2: