X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=fd.c;h=1053268e642147f20e43442b858f392babcb06f7;hp=a73325ba5af60adb712213aa789243dc02f74d90;hb=47a9983cc65ef57ad25c4ba3e16cabe48fd57b23;hpb=779cfd85fd90d1f9182deade08d5fe3f2f3a1530 diff --git a/fd.c b/fd.c index a73325ba..1053268e 100644 --- a/fd.c +++ b/fd.c @@ -1,5 +1,5 @@ /* - * Copyright (C) 2006-2012 Andre Noll + * Copyright (C) 2006-2014 Andre Noll * * Licensed under the GPL v2. For licencing details see COPYING. */ @@ -19,32 +19,56 @@ #include "fd.h" /** - * Write a buffer to a file descriptor, re-writing on short writes. + * Write an array of buffers to a file descriptor. * * \param fd The file descriptor. - * \param buf The buffer to write. - * \param len The number of bytes to write. + * \param iov Pointer to one or more buffers. + * \param iovcnt The number of buffers. * * EAGAIN/EWOULDBLOCK is not considered a fatal error condition. For example * DCCP CCID3 has a sending wait queue which fills up and is emptied * asynchronously. The EAGAIN case means that there is currently no space in * the wait queue, but this can change at any moment. * - * \return Negative on fatal errors, number of bytes written else. For blocking - * file descriptors this function returns either \a len or the error code of - * the fatal error that caused the last write call to fail. For nonblocking - * file descriptors there is a third possibility: A positive return value < \a - * len indicates that some bytes have been written but the next write would - * block. + * \return Negative on fatal errors, number of bytes written else. + * + * For blocking file descriptors, this function returns either the sum of all + * buffer sizes, or the error code of the fatal error that caused the last + * write call to fail. + * + * For nonblocking file descriptors there is a third possibility: Any positive + * return value less than the sum of the buffer sizes indicates that some bytes + * have been written but the next write would block. + * + * \sa writev(2), \ref xwrite(). */ -int xwrite(int fd, const char *buf, size_t len) +int xwritev(int fd, struct iovec *iov, int iovcnt) { size_t written = 0; - - while (written < len) { - ssize_t ret = write(fd, buf + written, len - written); + int i; + struct iovec saved_iov, *curiov; + + i = 0; + curiov = iov; + saved_iov = *curiov; + while (i < iovcnt && curiov->iov_len > 0) { + ssize_t ret = writev(fd, curiov, iovcnt - i); if (ret >= 0) { written += ret; + while (ret > 0) { + if (ret < curiov->iov_len) { + curiov->iov_base += ret; + curiov->iov_len -= ret; + break; + } + ret -= curiov->iov_len; + *curiov = saved_iov; + i++; + if (i >= iovcnt) + return written; + curiov++; + saved_iov = *curiov; + } continue; } if (errno == EINTR) @@ -66,6 +90,23 @@ int xwrite(int fd, const char *buf, size_t len) return written; } +/** + * Write a buffer to a file descriptor, re-writing on short writes. + * + * \param fd The file descriptor. + * \param buf The buffer to write. + * \param len The number of bytes to write. + * + * This is a simple wrapper for \ref xwritev(). + * + * \return The return value of the underlying call to \ref xwritev(). + */ +int xwrite(int fd, const char *buf, size_t len) +{ + struct iovec iov = {.iov_base = (void *)buf, .iov_len = len}; + return xwritev(fd, &iov, 1); +} + /** * Write all data to a file descriptor. * @@ -101,9 +142,11 @@ __printf_2_3 int write_va_buffer(int fd, const char *fmt, ...) { char *msg; int ret; + va_list ap; - PARA_VSPRINTF(fmt, msg); - ret = write_buffer(fd, msg); + va_start(ap, fmt); + ret = xvasprintf(&msg, fmt, ap); + ret = write_all(fd, msg, ret); free(msg); return ret; } @@ -119,13 +162,13 @@ __printf_2_3 int write_va_buffer(int fd, const char *fmt, ...) * * If \a rfds is not \p NULL and the (non-blocking) file descriptor \a fd is * not set in \a rfds, this function returns early without doing anything. - * Otherwise The function tries to read up to \a sz bytes from \a fd. As for - * xwrite(), EAGAIN is not considered an error condition. However, EOF - * is. + * Otherwise The function tries to read up to \a sz bytes from \a fd, where \a + * sz is the sum of the lengths of all vectors in \a iov. As for xwrite(), + * \p EAGAIN is not considered an error condition. However, \p EOF is. * * \return Zero or a negative error code. If the underlying call to readv(2) * returned zero (indicating an end of file condition) or failed for some - * reason other than \p EAGAIN, a negative return value is returned. + * reason other than \p EAGAIN, a negative error code is returned. * * In any case, \a num_bytes contains the number of bytes that have been * successfully read from \a fd (zero if the first readv() call failed with @@ -483,6 +526,7 @@ static int para_opendir(const char *dirname, DIR **dir, int *cwd) { int ret; + *dir = NULL; if (cwd) { ret = para_open(".", O_RDONLY, 0); if (ret < 0) @@ -574,6 +618,22 @@ int mmap_full_file(const char *path, int open_mode, void **map, goto out; } *size = file_status.st_size; + /* + * If the file is empty, *size is zero and mmap() would return EINVAL + * (Invalid argument). This error is common enough to spend an extra + * error code which explicitly states the problem. + */ + ret = -E_EMPTY; + if (*size == 0) + goto out; + /* + * If fd refers to a directory, mmap() returns ENODEV (No such device), + * at least on Linux. "Is a directory" seems to be more to the point. + */ + ret = -ERRNO_TO_PARA_ERROR(EISDIR); + if (S_ISDIR(file_status.st_mode)) + goto out; + ret = para_mmap(*size, mmap_prot, mmap_flags, fd, 0, map); out: if (ret < 0 || !fd_ptr)