X-Git-Url: https://mattmccutchen.net/rsync/rsync.git/blobdiff_plain/13c7bcbb2be2fc580af0ade159c2b85c4e3cd3b0..4e1f385711a5c5703eb1c3bbf21cc83c95fe3a6e:/io.c diff --git a/io.c b/io.c index 38386b69..60285656 100644 --- a/io.c +++ b/io.c @@ -1,19 +1,19 @@ /* -*- c-file-style: "linux" -*- - * - * Copyright (C) 1996-2001 by Andrew Tridgell + * + * Copyright (C) 1996-2001 by Andrew Tridgell * Copyright (C) Paul Mackerras 1996 * Copyright (C) 2001, 2002 by Martin Pool - * + * * 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., 675 Mass Ave, Cambridge, MA 02139, USA. @@ -22,7 +22,7 @@ /** * @file io.c * - * Socket and pipe IO utilities used in rsync. + * Socket and pipe I/O utilities used in rsync. * * rsync provides its own multiplexing system, which is used to send * stderr and stdout over a single socket. We need this because @@ -47,6 +47,7 @@ static time_t last_io; static int no_flush; extern int bwlimit; +extern size_t bwlimit_writemax; extern int verbose; extern int io_timeout; extern int am_server; @@ -63,9 +64,9 @@ const char phase_unknown[] = "unknown"; * not very helpful. So instead we try to make io_phase_name point to * something useful. * - * For buffered/multiplexed IO these names will be somewhat + * For buffered/multiplexed I/O these names will be somewhat * approximate; perhaps for ease of support we would rather make the - * buffer always flush when a single application-level IO finishes. + * buffer always flush when a single application-level I/O finishes. * * @todo Perhaps we want some simple stack functionality, but there's * no need to overdo it. @@ -137,7 +138,7 @@ 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 seconds - exiting\n", + rprintf(FERROR, "io timeout after %d seconds - exiting\n", (int)(t-last_io)); } exit_cleanup(RERR_TIMEOUT); @@ -146,7 +147,7 @@ static void check_timeout(void) /** Setup the fd used to receive MSG_* messages. Only needed when * we're the generator because the sender and receiver both use the - * multiplexed IO setup. */ + * multiplexed I/O setup. */ void set_msg_fd_in(int fd) { msg_fd_in = fd; @@ -154,7 +155,7 @@ void set_msg_fd_in(int fd) /** Setup the fd used to send our MSG_* messages. Only needed when * we're the receiver because the generator and the sender both use - * the multiplexed IO setup. */ + * the multiplexed I/O setup. */ void set_msg_fd_out(int fd) { msg_fd_out = fd; @@ -334,10 +335,9 @@ static void whine_about_eof(void) if (kludge_around_eof) exit_cleanup(0); else { - rprintf(FERROR, - "%s: connection unexpectedly closed " + rprintf(FERROR, RSYNC_NAME ": connection unexpectedly closed " "(%.0f bytes read so far)\n", - RSYNC_NAME, (double)stats.total_read); + (double)stats.total_read); exit_cleanup(RERR_STREAMIO); } @@ -349,14 +349,13 @@ static void die_from_readerr(int err) /* this prevents us trying to write errors on a dead socket */ io_multiplexing_close(); - rprintf(FERROR, "%s: read error: %s\n", - RSYNC_NAME, strerror(err)); + rsyserr(FERROR, err, "read error"); exit_cleanup(RERR_STREAMIO); } /** - * Read from a socket with IO timeout. return the number of bytes + * Read from a socket with I/O 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 @@ -368,7 +367,7 @@ static void die_from_readerr(int err) */ static int read_timeout(int fd, char *buf, size_t len) { - int n, ret=0; + int n, ret = 0; io_flush(NORMAL_FLUSH); @@ -508,8 +507,8 @@ static int read_timeout(int fd, char *buf, size_t len) whine_about_eof(); return -1; /* doesn't return */ } else if (n < 0) { - if (errno == EINTR || errno == EWOULDBLOCK || - errno == EAGAIN) + if (errno == EINTR || errno == EWOULDBLOCK + || errno == EAGAIN) continue; die_from_readerr(errno); } @@ -587,8 +586,8 @@ static void read_loop(int fd, char *buf, size_t len) /** * Read from the file descriptor handling multiplexing - return number * of bytes read. - * - * Never returns <= 0. + * + * Never returns <= 0. */ static int read_unbuffered(int fd, char *buf, size_t len) { @@ -671,7 +670,7 @@ static int read_unbuffered(int fd, char *buf, size_t len) static void readfd(int fd, char *buffer, size_t N) { int ret; - size_t total=0; + size_t total = 0; while (total < N) { ret = read_unbuffered(fd, buffer + total, N-total); @@ -741,22 +740,51 @@ unsigned char read_byte(int f) * use a bit less bandwidth than specified, because it doesn't make up * for slow periods. But arguably this is a feature. In addition, we * ought to take the time used to write the data into account. + * + * During some phases of big transfers (file FOO is uptodate) this is + * called with a small bytes_written every time. As the kernel has to + * round small waits up to guarantee that we actually wait at least the + * requested number of microseconds, this can become grossly inaccurate. + * We therefore keep track of the bytes we've written over time and only + * sleep when the accumulated delay is at least 1 tenth of a second. **/ static void sleep_for_bwlimit(int bytes_written) { - struct timeval tv; + static struct timeval prior_tv; + static long total_written = 0; + struct timeval tv, start_tv; + long elapsed_usec, sleep_usec; + +#define ONE_SEC 1000000L /* # of microseconds in a second */ if (!bwlimit) return; - assert(bytes_written > 0); - assert(bwlimit > 0); + total_written += bytes_written; + + gettimeofday(&start_tv, NULL); + if (prior_tv.tv_sec) { + elapsed_usec = (start_tv.tv_sec - prior_tv.tv_sec) * ONE_SEC + + (start_tv.tv_usec - prior_tv.tv_usec); + total_written -= elapsed_usec * bwlimit / (ONE_SEC/1024); + if (total_written < 0) + total_written = 0; + } - tv.tv_usec = bytes_written * 1000 / bwlimit; - tv.tv_sec = tv.tv_usec / 1000000; - tv.tv_usec = tv.tv_usec % 1000000; + sleep_usec = total_written * (ONE_SEC/1024) / bwlimit; + if (sleep_usec < ONE_SEC / 10) { + prior_tv = start_tv; + return; + } + tv.tv_sec = sleep_usec / ONE_SEC; + tv.tv_usec = sleep_usec % ONE_SEC; select(0, NULL, NULL, NULL, &tv); + + gettimeofday(&prior_tv, NULL); + elapsed_usec = (prior_tv.tv_sec - start_tv.tv_sec) * ONE_SEC + + (prior_tv.tv_usec - start_tv.tv_usec); + total_written = (sleep_usec - elapsed_usec) * bwlimit / (ONE_SEC/1024); } @@ -785,7 +813,7 @@ static void writefd_unbuffered(int fd,char *buf,size_t len) if (msg_fd_in >= 0) { FD_ZERO(&r_fds); FD_SET(msg_fd_in,&r_fds); - if (msg_fd_in > fd_count) + if (msg_fd_in > fd_count) fd_count = msg_fd_in; } @@ -814,6 +842,8 @@ static void writefd_unbuffered(int fd,char *buf,size_t len) if (FD_ISSET(fd, &w_fds)) { int ret; size_t n = len-total; + if (bwlimit && n > bwlimit_writemax) + n = bwlimit_writemax; ret = write(fd,buf+total,n); if (ret < 0) { @@ -829,15 +859,14 @@ static void writefd_unbuffered(int fd,char *buf,size_t len) /* Don't try to write errors back * across the stream */ io_multiplexing_close(); - rprintf(FERROR, RSYNC_NAME - ": writefd_unbuffered failed to write %ld bytes: phase \"%s\": %s\n", - (long) len, io_write_phase, - strerror(errno)); + rsyserr(FERROR, errno, + "writefd_unbuffered failed to write %ld bytes: phase \"%s\"", + (long) len, io_write_phase); exit_cleanup(RERR_STREAMIO); } sleep_for_bwlimit(ret); - + total += ret; if (io_timeout) @@ -896,7 +925,7 @@ static void mplex_write(int fd, enum msgcode code, char *buf, size_t len) void io_flush(int flush_it_all) { int fd = multiplex_out_fd; - + msg_list_push(flush_it_all); if (!io_buffer_count || no_flush) @@ -1006,10 +1035,11 @@ void write_byte(int f,unsigned char c) /** - * Read a line of up to @p maxlen characters into @p buf. Does not - * contain a trailing newline or carriage return. + * Read a line of up to @p maxlen characters into @p buf (not counting + * the trailing null). Strips the (required) trailing newline and all + * carriage returns. * - * @return 1 for success; 0 for io error or truncation. + * @return 1 for success; 0 for I/O error or truncation. **/ int read_line(int f, char *buf, size_t maxlen) { @@ -1018,27 +1048,21 @@ int read_line(int f, char *buf, size_t maxlen) read_buf(f, buf, 1); if (buf[0] == 0) return 0; - if (buf[0] == '\n') { - buf[0] = 0; + if (buf[0] == '\n') break; - } if (buf[0] != '\r') { buf++; maxlen--; } } - if (maxlen == 0) { - *buf = 0; - return 0; - } - - return 1; + *buf = '\0'; + return maxlen > 0; } void io_printf(int fd, const char *format, ...) { - va_list ap; + va_list ap; char buf[1024]; int len;