liblog: split out transports into separate files

Create config_logger, logger and logger_read to house the log
interfaces. Add fake_logger, logd_logger and pmsg_logger to
house the write and read transports. Allows for an easier and
direct path to add new transports to the library.

SideEffects: None, logger benchmark performance unaffected

Bug: 27176738
Bug: 27405083
Change-Id: I01b38637334a5242905c8c89f6ab0a92e2540008
diff --git a/liblog/logger.h b/liblog/logger.h
new file mode 100644
index 0000000..61bc396
--- /dev/null
+++ b/liblog/logger.h
@@ -0,0 +1,159 @@
+/*
+ * Copyright (C) 2016 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#ifndef _LIBLOG_LOGGER_H__
+#define _LIBLOG_LOGGER_H__
+
+#include <stdbool.h>
+#include <log/uio.h>
+
+#include <cutils/list.h>
+#include <log/log.h>
+#include <log/log_read.h>
+#include <log/logger.h>
+
+#include "log_portability.h"
+
+__BEGIN_DECLS
+
+/* Union, sock or fd of zero is not allowed unless static initialized */
+union android_log_context {
+  void *private;
+  int sock;
+  int fd;
+  struct listnode *node;
+};
+
+struct android_log_transport_write {
+  struct listnode node;
+  const char *name;
+  union android_log_context context; /* Initialized by static allocation */
+
+  int (*available)(log_id_t logId);
+  int (*open)();
+  void (*close)();
+  int (*write)(log_id_t logId, struct timespec *ts, struct iovec *vec, size_t nr);
+};
+
+struct android_log_logger_list;
+struct android_log_transport_context;
+struct android_log_logger;
+
+struct android_log_transport_read {
+  struct listnode node;
+  const char *name;
+
+  int (*available)(log_id_t logId);
+  int (*version)(struct android_log_logger *logger,
+                 struct android_log_transport_context *transp);
+  void (*close)(struct android_log_logger_list *logger_list,
+                struct android_log_transport_context *transp);
+
+  /*
+   * Expect all to instantiate open on any call, so we do not have
+   * an expicit open call
+   */
+  int (*read)(struct android_log_logger_list *logger_list,
+              struct android_log_transport_context *transp,
+              struct log_msg *log_msg);
+  /* Assumption is only called if not ANDROID_LOG_NONBLOCK */
+  int (*poll)(struct android_log_logger_list *logger_list,
+              struct android_log_transport_context *transp);
+
+  int (*clear)(struct android_log_logger *logger,
+               struct android_log_transport_context *transp);
+  ssize_t (*setSize)(struct android_log_logger *logger,
+                     struct android_log_transport_context *transp,
+                     size_t size);
+  ssize_t (*getSize)(struct android_log_logger *logger,
+                     struct android_log_transport_context *transp);
+  ssize_t (*getReadableSize)(struct android_log_logger *logger,
+                             struct android_log_transport_context *transp);
+
+  ssize_t (*getPrune)(struct android_log_logger_list *logger_list,
+                      struct android_log_transport_context *transp,
+                      char *buf, size_t len);
+  ssize_t (*setPrune)(struct android_log_logger_list *logger_list,
+                      struct android_log_transport_context *transp,
+                      char *buf, size_t len);
+  ssize_t (*getStats)(struct android_log_logger_list *logger_list,
+                      struct android_log_transport_context *transp,
+                      char *buf, size_t len);
+};
+
+struct android_log_logger_list {
+  struct listnode logger;
+  struct listnode transport;
+  int mode;
+  unsigned int tail;
+  log_time start;
+  pid_t pid;
+};
+
+struct android_log_logger {
+  struct listnode node;
+  struct android_log_logger_list *parent;
+
+  log_id_t logId;
+};
+
+struct android_log_transport_context {
+  struct listnode node;
+  union android_log_context context; /* zero init per-transport context */
+  struct android_log_logger_list *parent;
+
+  struct android_log_transport_read *transport;
+  unsigned logMask;
+  int ret;
+  struct log_msg logMsg; /* valid is logMsg.len != 0 */
+};
+
+/* assumes caller has structures read-locked, single threaded, or fenced */
+#define transport_context_for_each(transp, logger_list)              \
+  for (transp = node_to_item((logger_list)->transport.next,          \
+                             struct android_log_transport_context,   \
+                             node);                                  \
+       (transp != node_to_item(&(logger_list)->transport,            \
+                               struct android_log_transport_context, \
+                               node)) &&                             \
+           (transp->parent == (logger_list));                        \
+       transp = node_to_item(transp->node.next,                      \
+                             struct android_log_transport_context, node))
+
+#define logger_for_each(logp, logger_list)                          \
+    for (logp = node_to_item((logger_list)->logger.next,            \
+                             struct android_log_logger, node);      \
+         (logp != node_to_item(&(logger_list)->logger,              \
+                               struct android_log_logger, node)) && \
+             (logp->parent == (logger_list));                       \
+         logp = node_to_item((logp)->node.next,                     \
+                             struct android_log_logger, node))
+
+/* OS specific dribs and drabs */
+
+#if defined(_WIN32)
+typedef uint32_t uid_t;
+#endif
+
+LIBLOG_HIDDEN uid_t __android_log_uid();
+LIBLOG_HIDDEN pid_t __android_log_pid();
+LIBLOG_HIDDEN void __android_log_lock();
+LIBLOG_HIDDEN int __android_log_trylock();
+LIBLOG_HIDDEN void __android_log_unlock();
+
+__END_DECLS
+
+#endif /* _LIBLOG_LOGGER_H__ */