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/*
 * Utility routines.
 *
 * Licensed under GPLv2 or later, see file COPYING in this tarball for details.
 */
#include "abrtlib.h"

ssize_t safe_read(int fd, void *buf, size_t count)
{
	ssize_t n;

	do {
		n = read(fd, buf, count);
	} while (n < 0 && errno == EINTR);

	return n;
}

ssize_t full_read(int fd, void *buf, size_t len)
{
	ssize_t cc;
	ssize_t total;

	total = 0;

	while (len) {
		cc = safe_read(fd, buf, len);

		if (cc < 0) {
			if (total) {
				/* we already have some! */
				/* user can do another read to know the error code */
				return total;
			}
			return cc; /* read() returns -1 on failure. */
		}
		if (cc == 0)
			break;
		buf = ((char *)buf) + cc;
		total += cc;
		len -= cc;
	}

	return total;
}

/* Die with an error message if we can't read the entire buffer. */
void xread(int fd, void *buf, size_t count)
{
	if (count) {
		ssize_t size = full_read(fd, buf, count);
		if ((size_t)size != count)
			error_msg_and_die("short read");
	}
}

ssize_t safe_write(int fd, const void *buf, size_t count)
{
	ssize_t n;

	do {
		n = write(fd, buf, count);
	} while (n < 0 && errno == EINTR);

	return n;
}

ssize_t full_write(int fd, const void *buf, size_t len)
{
	ssize_t cc;
	ssize_t total;

	total = 0;

	while (len) {
		cc = safe_write(fd, buf, len);

		if (cc < 0) {
			if (total) {
				/* we already wrote some! */
				/* user can do another write to know the error code */
				return total;
			}
			return cc;	/* write() returns -1 on failure. */
		}

		total += cc;
		buf = ((const char *)buf) + cc;
		len -= cc;
	}

	return total;
}