liblog: split out transports into separate files

(cherry pick from commit 018a96d03f0d452bf078084eedcd5693da42308d)

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/fake_writer.c b/liblog/fake_writer.c
new file mode 100644
index 0000000..dab8bc5
--- /dev/null
+++ b/liblog/fake_writer.c
@@ -0,0 +1,82 @@
+/*
+ * Copyright (C) 2007-2016 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.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include <log/log.h>
+
+#include "config_write.h"
+#include "fake_log_device.h"
+#include "log_portability.h"
+#include "logger.h"
+
+static int fakeOpen();
+static void fakeClose();
+static int fakeWrite(log_id_t log_id, struct timespec *ts,
+                     struct iovec *vec, size_t nr);
+
+static int logFds[(int)LOG_ID_MAX] = { -1, -1, -1, -1, -1, -1 };
+
+LIBLOG_HIDDEN struct android_log_transport_write fakeLoggerWrite = {
+    .node = { &fakeLoggerWrite.node, &fakeLoggerWrite.node },
+    .context.private = &logFds,
+    .name = "fake",
+    .available = NULL,
+    .open = fakeOpen,
+    .close = fakeClose,
+    .write = fakeWrite,
+};
+
+static int fakeOpen() {
+    int i;
+
+    for (i = 0; i < LOG_ID_MAX; i++) {
+        char buf[sizeof("/dev/log_security")];
+        snprintf(buf, sizeof(buf), "/dev/log_%s", android_log_id_to_name(i));
+        logFds[i] = fakeLogOpen(buf, O_WRONLY);
+    }
+    return 0;
+}
+
+static void fakeClose() {
+    int i;
+
+    for (i = 0; i < LOG_ID_MAX; i++) {
+        fakeLogClose(logFds[i]);
+        logFds[i] = -1;
+    }
+}
+
+static int fakeWrite(log_id_t log_id, struct timespec *ts __unused,
+                      struct iovec *vec, size_t nr)
+{
+    ssize_t ret;
+    int logFd;
+
+    if (/*(int)log_id >= 0 &&*/ (int)log_id >= (int)LOG_ID_MAX) {
+        return -EBADF;
+    }
+
+    logFd = logFds[(int)log_id];
+    ret = TEMP_FAILURE_RETRY(fakeLogWritev(logFd, vec, nr));
+    if (ret < 0) {
+        ret = -errno;
+    }
+
+    return ret;
+}