client: splitted client.c into several pieces

The soure file client.c has nearly 1000 lines, time for splitting it
into smaller pieces to improve readability.

src/client_read.c

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2003-2009 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "client_internal.h"
+#include "fifo_buffer.h"
+
+#include <assert.h>
+#include <string.h>
+
+static char *
+client_read_line(struct client *client)
+{
+	const char *p, *newline;
+	size_t length;
+	char *line;
+
+	p = fifo_buffer_read(client->input, &length);
+	if (p == NULL)
+		return NULL;
+
+	newline = memchr(p, '\n', length);
+	if (newline == NULL)
+		return NULL;
+
+	line = g_strndup(p, newline - p);
+	fifo_buffer_consume(client->input, newline - p + 1);
+
+	return g_strchomp(line);
+}
+
+static enum command_return
+client_input_received(struct client *client, size_t bytesRead)
+{
+	char *line;
+
+	fifo_buffer_append(client->input, bytesRead);
+
+	/* process all lines */
+
+	while ((line = client_read_line(client)) != NULL) {
+		enum command_return ret = client_process_line(client, line);
+		g_free(line);
+
+		if (ret == COMMAND_RETURN_KILL ||
+		    ret == COMMAND_RETURN_CLOSE)
+			return ret;
+		if (client_is_expired(client))
+			return COMMAND_RETURN_CLOSE;
+	}
+
+	return COMMAND_RETURN_OK;
+}
+
+enum command_return
+client_read(struct client *client)
+{
+	char *p;
+	size_t max_length;
+	GError *error = NULL;
+	GIOStatus status;
+	gsize bytes_read;
+
+	assert(client != NULL);
+	assert(client->channel != NULL);
+
+	p = fifo_buffer_write(client->input, &max_length);
+	if (p == NULL) {
+		g_warning("[%u] buffer overflow", client->num);
+		return COMMAND_RETURN_CLOSE;
+	}
+
+	status = g_io_channel_read_chars(client->channel, p, max_length,
+					 &bytes_read, &error);
+	switch (status) {
+	case G_IO_STATUS_NORMAL:
+		return client_input_received(client, bytes_read);
+
+	case G_IO_STATUS_AGAIN:
+		/* try again later, after select() */
+		return COMMAND_RETURN_OK;
+
+	case G_IO_STATUS_EOF:
+		/* peer disconnected */
+		return COMMAND_RETURN_CLOSE;
+
+	case G_IO_STATUS_ERROR:
+		/* I/O error */
+		g_warning("failed to read from client %d: %s",
+			  client->num, error->message);
+		g_error_free(error);
+		return COMMAND_RETURN_CLOSE;
+	}
+
+	/* unreachable */
+	return COMMAND_RETURN_CLOSE;
+}