Initial commit

2018-02-14 15:05:29 +09:00
commit 20f797d2f6
8093 changed files with 1360150 additions and 0 deletions
@@ -0,0 +1,180 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// Author: oschaaf@we-amp.com (Otto van der Schaaf)
+
+extern "C" {
+
+#include <ngx_channel.h>
+
+}
+
+#include "ngx_event_connection.h"
+
+#include "pagespeed/kernel/base/google_message_handler.h"
+#include "pagespeed/kernel/base/message_handler.h"
+
+namespace net_instaweb {
+
+  NgxEventConnection::NgxEventConnection(callbackPtr callback)
+    : event_handler_(callback) {
+}
+
+bool NgxEventConnection::Init(ngx_cycle_t* cycle) {
+  int file_descriptors[2];
+
+  if (pipe(file_descriptors) != 0) {
+    ngx_log_error(NGX_LOG_EMERG, cycle->log, 0, "pagespeed: pipe() failed");
+    return false;
+  }
+  if (ngx_nonblocking(file_descriptors[0]) == -1) {
+    ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
+                  ngx_nonblocking_n "pagespeed:  pipe[0] failed");
+  } else if (ngx_nonblocking(file_descriptors[1]) == -1) {
+    ngx_log_error(NGX_LOG_EMERG, cycle->log, ngx_socket_errno,
+                  ngx_nonblocking_n "pagespeed:  pipe[1] failed");
+  } else if (!CreateNgxConnection(cycle, file_descriptors[0])) {
+    ngx_log_error(NGX_LOG_EMERG, cycle->log, 0,
+                  "pagespeed: failed to create connection.");
+  } else {
+    pipe_read_fd_ = file_descriptors[0];
+    pipe_write_fd_ = file_descriptors[1];
+    // Attempt to bump the pipe capacity, because running out of buffer space
+    // can potentially lead up to writes spinning on EAGAIN.
+    // See https://github.com/pagespeed/ngx_pagespeed/issues/1380
+    // TODO(oschaaf): Consider implementing a queueing mechanism for retrying
+    // failed writes.
+#ifdef F_SETPIPE_SZ
+    fcntl(pipe_write_fd_, F_SETPIPE_SZ, 200*1024 /* minimal amount of bytes */);
+#endif
+    return true;
+  }
+  close(file_descriptors[0]);
+  close(file_descriptors[1]);
+  return false;
+}
+
+bool NgxEventConnection::CreateNgxConnection(ngx_cycle_t* cycle,
+                                             ngx_fd_t pipe_fd) {
+  // pipe_fd (the read side of the pipe will end up as c->fd on the
+  // underlying ngx_connection_t that gets created here)
+  ngx_int_t rc = ngx_add_channel_event(cycle, pipe_fd, NGX_READ_EVENT,
+      &NgxEventConnection::ReadEventHandler);
+  return rc  == NGX_OK;
+}
+
+void NgxEventConnection::ReadEventHandler(ngx_event_t* ev) {
+  ngx_connection_t* c = static_cast<ngx_connection_t*>(ev->data);
+  ngx_int_t result = ngx_handle_read_event(ev, 0);
+  if (result != NGX_OK) {
+    CHECK(false) << "pagespeed: ngx_handle_read_event error: " << result;
+  }
+
+  if (ev->timedout) {
+    ev->timedout = 0;
+    return;
+  }
+
+  if (!NgxEventConnection::ReadAndNotify(c->fd)) {
+    // This was copied from ngx_channel_handler(): for epoll, we need to call
+    // ngx_del_conn(). Sadly, no documentation as to why.
+    if (ngx_event_flags & NGX_USE_EPOLL_EVENT) {
+      ngx_del_conn(c, 0);
+    }
+    ngx_close_connection(c);
+    ngx_del_event(ev, NGX_READ_EVENT, 0);
+  }
+}
+
+// Deserialize ps_event_data's from the pipe as they become available.
+// Subsequently do some bookkeeping, cleanup, and error checking to keep
+// the mess out of ps_base_fetch_handler.
+bool NgxEventConnection::ReadAndNotify(ngx_fd_t fd) {
+  while (true) {
+    // We read only one ps_event_data at a time for now:
+    // We can end up recursing all the way and end up calling ourselves here.
+    // If that happens in the middle of looping over multiple ps_event_data's we
+    // have obtained with read(), the results from the next read() will make us
+    // process events out of order. Which can give headaches.
+    // Alternatively, we could maintain a queue to make sure we process in
+    // sequence
+    ps_event_data data;
+    ngx_int_t size = read(fd, static_cast<void*>(&data), sizeof(data));
+
+    if (size == -1) {
+      if (errno == EINTR) {
+        continue;
+      // TODO(oschaaf): should we worry about spinning here?
+      } else if (ngx_errno == EAGAIN || ngx_errno == EWOULDBLOCK) {
+        return true;
+      }
+    }
+
+    if (size <= 0) {
+      return false;
+    }
+
+    data.connection->event_handler_(data);
+    return true;
+  }
+}
+
+bool NgxEventConnection::WriteEvent(void* sender) {
+  return WriteEvent('X' /* Anything char is fine */, sender);
+}
+
+bool NgxEventConnection::WriteEvent(char type, void* sender) {
+  ssize_t size = 0;
+  ps_event_data data;
+
+  ngx_memzero(&data, sizeof(data));
+  data.type = type;
+  data.sender = sender;
+  data.connection = this;
+
+  while (true) {
+    size = write(pipe_write_fd_,
+                 static_cast<void*>(&data), sizeof(data));
+    if (size == sizeof(data)) {
+      return true;
+    } else if (size == -1) {
+      // TODO(oschaaf): should we worry about spinning here?
+      if (ngx_errno == EINTR || ngx_errno == EAGAIN
+          || ngx_errno == EWOULDBLOCK) {
+        continue;
+      } else {
+        return false;
+      }
+    } else {
+      CHECK(false) << "pagespeed: unexpected return value from write(): "
+                   << size;
+    }
+  }
+  CHECK(false) << "Should not get here";
+  return false;
+}
+
+// Reads and processes what is available in the pipe.
+void NgxEventConnection::Drain() {
+  NgxEventConnection::ReadAndNotify(pipe_read_fd_);
+}
+
+void NgxEventConnection::Shutdown() {
+  close(pipe_write_fd_);
+  close(pipe_read_fd_);
+}
+
+}  // namespace net_instaweb