Add a little more protocol documentation.

[rsync/rsync.git] / io.c

diff --git a/io.c b/io.c
index fbaf6a3..dac0744 100644 (file)
--- a/io.c
+++ b/io.c
@@ -1,5 +1,6 @@
-/* 
-   Copyright (C) Andrew Tridgell 1996
+/* -*- c-file-style: "linux" -*-
+   
+   Copyright (C) 1996-2001 by Andrew Tridgell 
    Copyright (C) Paul Mackerras 1996
    
    This program is free software; you can redistribute it and/or modify
@@ -27,6 +28,8 @@
 /* if no timeout is specified then use a 60 second select timeout */
 #define SELECT_TIMEOUT 60
 
+extern int bwlimit;
+
 static int io_multiplexing_out;
 static int io_multiplexing_in;
 static int multiplex_in_fd;
@@ -37,20 +40,16 @@ extern int verbose;
 extern int io_timeout;
 extern struct stats stats;
 
-static int buffer_f_in = -1;
 static int io_error_fd = -1;
 
 static void read_loop(int fd, char *buf, int len);
 
-void setup_readbuffer(int f_in)
-{
-       buffer_f_in = f_in;
-}
-
 static void check_timeout(void)
 {
        extern int am_server, am_daemon;
        time_t t;
+
+       err_list_push();
        
        if (!io_timeout) return;
 
@@ -63,7 +62,7 @@ static void check_timeout(void)
 
        if (last_io && io_timeout && (t-last_io) >= io_timeout) {
                if (!am_server && !am_daemon) {
-                       rprintf(FERROR,"io timeout after %d second - exiting\n", 
+                       rprintf(FERROR,"io timeout after %d seconds - exiting\n", 
                                (int)(t-last_io));
                }
                exit_cleanup(RERR_TIMEOUT);
@@ -84,6 +83,8 @@ static void read_error_fd(void)
        int fd = io_error_fd;
        int tag, len;
 
+        /* io_error_fd is temporarily disabled -- is this meant to
+         * prevent indefinite recursion? */
        io_error_fd = -1;
 
        read_loop(fd, buf, 4);
@@ -107,9 +108,17 @@ static void read_error_fd(void)
 
 static int no_flush;
 
-/* read from a socket with IO timeout. return the number of
-   bytes read. If no bytes can be read then exit, never return
-   a number <= 0 */
+/*
+ * Read from a socket with IO timeout. return the number of bytes
+ * read. If no bytes can be read then exit, never return a number <= 0.
+ *
+ * TODO: If the remote shell connection fails, then current versions
+ * actually report an "unexpected EOF" error here.  Since it's a
+ * fairly common mistake to try to use rsh when ssh is required, we
+ * should trap that: if we fail to read any data at all, we should
+ * give a better explanation.  We can tell whether the connection has
+ * started by looking e.g. at whether the remote version is known yet.
+ */
 static int read_timeout(int fd, char *buf, int len)
 {
        int n, ret=0;
@@ -170,7 +179,10 @@ static int read_timeout(int fd, char *buf, int len)
 
                if (n == 0) {
                        if (eof_error) {
-                               rprintf(FERROR,"unexpected EOF in read_timeout\n");
+                               rprintf(FERROR,
+                                        "%s: connection to server unexpectedly closed"
+                                        " (%.0f bytes read so far)\n",
+                                        RSYNC_NAME, (double)stats.total_read);
                        }
                        exit_cleanup(RERR_STREAMIO);
                }
@@ -321,11 +333,7 @@ unsigned char read_byte(int f)
        return c;
 }
 
-
-
-/* write len bytes to fd, possibly reading from buffer_f_in if set
-   in order to unclog the pipe. don't return until all len
-   bytes have been written */
+/* write len bytes to fd */
 static void writefd_unbuffered(int fd,char *buf,int len)
 {
        int total = 0;
@@ -333,6 +341,8 @@ static void writefd_unbuffered(int fd,char *buf,int len)
        int fd_count, count;
        struct timeval tv;
 
+       err_list_push();
+
        no_flush++;
 
        while (total < len) {
@@ -371,7 +381,6 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 
                if (FD_ISSET(fd, &w_fds)) {
                        int ret, n = len-total;
-                       
                        ret = write(fd,buf+total,n);
 
                        if (ret == -1 && errno == EINTR) {
@@ -380,14 +389,31 @@ static void writefd_unbuffered(int fd,char *buf,int len)
 
                        if (ret == -1 && 
                            (errno == EWOULDBLOCK || errno == EAGAIN)) {
+                               msleep(1);
                                continue;
                        }
 
                        if (ret <= 0) {
-                               rprintf(FERROR,"erroring writing %d bytes - exiting\n", len);
+                               rprintf(FERROR,
+                                       "error writing %d unbuffered bytes"
+                                       " - exiting: %s\n", len,
+                                       strerror(errno));
                                exit_cleanup(RERR_STREAMIO);
                        }
 
+                       /* Sleep after writing to limit I/O bandwidth */
+                       if (bwlimit)
+                       {
+                           tv.tv_sec = 0;
+                           tv.tv_usec = ret * 1000 / bwlimit;
+                           while (tv.tv_usec > 1000000)
+                           {
+                               tv.tv_sec++;
+                               tv.tv_usec -= 1000000;
+                           }
+                           select(0, NULL, NULL, NULL, &tv);
+                       }
+ 
                        total += ret;
 
                        if (io_timeout)
@@ -439,6 +465,9 @@ static void mplex_write(int fd, enum logcode code, char *buf, int len)
 void io_flush(void)
 {
        int fd = multiplex_out_fd;
+
+       err_list_push();
+
        if (!io_buffer_count || no_flush) return;
 
        if (io_multiplexing_out) {
@@ -449,6 +478,8 @@ void io_flush(void)
        io_buffer_count = 0;
 }
 
+
+/* XXX: fd is ignored, which seems a little strange. */
 void io_end_buffering(int fd)
 {
        io_flush();
@@ -462,6 +493,8 @@ static void writefd(int fd,char *buf,int len)
 {
        stats.total_written += len;
 
+       err_list_push();
+
        if (!io_buffer || fd != multiplex_out_fd) {
                writefd_unbuffered(fd, buf, len);
                return;
@@ -488,6 +521,11 @@ void write_int(int f,int32 x)
        writefd(f,b,4);
 }
 
+
+/*
+ * Note: int64 may actually be a 32-bit type if ./configure couldn't find any
+ * 64-bit types on this platform.
+ */
 void write_longint(int f, int64 x)
 {
        extern int remote_version;
@@ -557,7 +595,7 @@ void io_printf(int fd, const char *format, ...)
        int len;
        
        va_start(ap, format);
-       len = vslprintf(buf, sizeof(buf), format, ap);
+       len = vsnprintf(buf, sizeof(buf), format, ap);
        va_end(ap);
 
        if (len < 0) exit_cleanup(RERR_STREAMIO);
@@ -594,22 +632,9 @@ int io_multiplex_write(enum logcode code, char *buf, int len)
        return 1;
 }
 
-/* write a message to the special error fd */
-int io_error_write(int f, enum logcode code, char *buf, int len)
-{
-       if (f == -1) return 0;
-       mplex_write(f, code, buf, len);
-       return 1;
-}
-
 /* stop output multiplexing */
 void io_multiplexing_close(void)
 {
        io_multiplexing_out = 0;
 }
 
-void io_close_input(int fd)
-{
-       buffer_f_in = -1;
-}
-