/* * Copyright (C) 2003-2010 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 "config.h" #include "client_internal.h" #include <assert.h> #include <string.h> #include <stdio.h> static size_t client_write_deferred_buffer(struct client *client, const struct deferred_buffer *buffer) { GError *error = NULL; GIOStatus status; gsize bytes_written; assert(client != NULL); assert(client->channel != NULL); assert(buffer != NULL); status = g_io_channel_write_chars (client->channel, buffer->data, buffer->size, &bytes_written, &error); switch (status) { case G_IO_STATUS_NORMAL: return bytes_written; case G_IO_STATUS_AGAIN: return 0; case G_IO_STATUS_EOF: /* client has disconnected */ client_set_expired(client); return 0; case G_IO_STATUS_ERROR: /* I/O error */ client_set_expired(client); g_warning("failed to flush buffer for %i: %s", client->num, error->message); g_error_free(error); return 0; } /* unreachable */ return 0; } void client_write_deferred(struct client *client) { size_t ret; while (!g_queue_is_empty(client->deferred_send)) { struct deferred_buffer *buf = g_queue_peek_head(client->deferred_send); assert(buf->size > 0); assert(buf->size <= client->deferred_bytes); ret = client_write_deferred_buffer(client, buf); if (ret == 0) break; if (ret < buf->size) { assert(client->deferred_bytes >= (size_t)ret); client->deferred_bytes -= ret; buf->size -= ret; memmove(buf->data, buf->data + ret, buf->size); break; } else { size_t decr = sizeof(*buf) - sizeof(buf->data) + buf->size; assert(client->deferred_bytes >= decr); client->deferred_bytes -= decr; g_free(buf); g_queue_pop_head(client->deferred_send); } g_timer_start(client->last_activity); } if (g_queue_is_empty(client->deferred_send)) { g_debug("[%u] buffer empty %lu", client->num, (unsigned long)client->deferred_bytes); assert(client->deferred_bytes == 0); } } static void client_defer_output(struct client *client, const void *data, size_t length) { size_t alloc; struct deferred_buffer *buf; assert(length > 0); alloc = sizeof(*buf) - sizeof(buf->data) + length; client->deferred_bytes += alloc; if (client->deferred_bytes > client_max_output_buffer_size) { g_warning("[%u] output buffer size (%lu) is " "larger than the max (%lu)", client->num, (unsigned long)client->deferred_bytes, (unsigned long)client_max_output_buffer_size); /* cause client to close */ client_set_expired(client); return; } buf = g_malloc(alloc); buf->size = length; memcpy(buf->data, data, length); g_queue_push_tail(client->deferred_send, buf); } static void client_write_direct(struct client *client, const char *data, size_t length) { GError *error = NULL; GIOStatus status; gsize bytes_written; assert(client != NULL); assert(client->channel != NULL); assert(data != NULL); assert(length > 0); assert(g_queue_is_empty(client->deferred_send)); status = g_io_channel_write_chars(client->channel, data, length, &bytes_written, &error); switch (status) { case G_IO_STATUS_NORMAL: case G_IO_STATUS_AGAIN: break; case G_IO_STATUS_EOF: /* client has disconnected */ client_set_expired(client); return; case G_IO_STATUS_ERROR: /* I/O error */ client_set_expired(client); g_warning("failed to write to %i: %s", client->num, error->message); g_error_free(error); return; } if (bytes_written < length) client_defer_output(client, data + bytes_written, length - bytes_written); if (!g_queue_is_empty(client->deferred_send)) g_debug("[%u] buffer created", client->num); } void client_write_output(struct client *client) { if (client_is_expired(client) || !client->send_buf_used) return; if (!g_queue_is_empty(client->deferred_send)) { client_defer_output(client, client->send_buf, client->send_buf_used); if (client_is_expired(client)) return; /* try to flush the deferred buffers now; the current server command may take too long to finish, and meanwhile try to feed output to the client, otherwise it will time out. One reason why deferring is slow might be that currently each client_write() allocates a new deferred buffer. This should be optimized after MPD 0.14. */ client_write_deferred(client); } else client_write_direct(client, client->send_buf, client->send_buf_used); client->send_buf_used = 0; } /** * Write a block of data to the client. */ static void client_write(struct client *client, const char *buffer, size_t buflen) { /* if the client is going to be closed, do nothing */ if (client_is_expired(client)) return; while (buflen > 0 && !client_is_expired(client)) { size_t copylen; assert(client->send_buf_used < sizeof(client->send_buf)); copylen = sizeof(client->send_buf) - client->send_buf_used; if (copylen > buflen) copylen = buflen; memcpy(client->send_buf + client->send_buf_used, buffer, copylen); buflen -= copylen; client->send_buf_used += copylen; buffer += copylen; if (client->send_buf_used >= sizeof(client->send_buf)) client_write_output(client); } } void client_puts(struct client *client, const char *s) { client_write(client, s, strlen(s)); } void client_vprintf(struct client *client, const char *fmt, va_list args) { #ifndef G_OS_WIN32 va_list tmp; int length; char *buffer; va_copy(tmp, args); length = vsnprintf(NULL, 0, fmt, tmp); va_end(tmp); if (length <= 0) /* wtf.. */ return; buffer = g_malloc(length + 1); vsnprintf(buffer, length + 1, fmt, args); client_write(client, buffer, length); g_free(buffer); #else /* On mingw32, snprintf() expects a 64 bit integer instead of a "long int" for "%li". This is not consistent with our expectation, so we're using plain sprintf() here, hoping the static buffer is large enough. Sorry for this hack, but WIN32 development is so painful, I'm not in the mood to do it properly now. */ static char buffer[4096]; vsprintf(buffer, fmt, args); client_write(client, buffer, strlen(buffer)); #endif } G_GNUC_PRINTF(2, 3) void client_printf(struct client *client, const char *fmt, ...) { va_list args; va_start(args, fmt); client_vprintf(client, fmt, args); va_end(args); }