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/* Eliminate teeny little writes. patch submitted by
Rob Ross <rbross@parl.ces.clemson.edu> --Monty 19991008 */
#include <string.h>
#include <unistd.h>
#include <errno.h>
#include <stdio.h>
#define OUTBUFSZ 32*1024
#include "utils.h"
extern long blocking_write(int outf, char *buffer, long num);
/* GLOBALS FOR BUFFERING CALLS */
static int bw_fd = -1;
static long bw_pos = 0;
static char bw_outbuf[OUTBUFSZ];
/* buffering_write() - buffers data to a specified size before writing.
*
* Restrictions:
* - MUST CALL BUFFERING_CLOSE() WHEN FINISHED!!!
*
*/
long buffering_write(int fd, char *buffer, long num)
{
if (fd != bw_fd) {
/* clean up after buffering for some other file */
if (bw_fd >= 0 && bw_pos > 0) {
if (blocking_write(bw_fd, bw_outbuf, bw_pos)) {
perror("write (in buffering_write, flushing)");
}
}
bw_fd = fd;
bw_pos = 0;
}
if (bw_pos + num > OUTBUFSZ) {
/* fill our buffer first, then write, then modify buffer and num */
memcpy(&bw_outbuf[bw_pos], buffer, OUTBUFSZ - bw_pos);
if (blocking_write(fd, bw_outbuf, OUTBUFSZ)) {
perror("write (in buffering_write, full buffer)");
return(-1);
}
num -= (OUTBUFSZ - bw_pos);
buffer += (OUTBUFSZ - bw_pos);
bw_pos = 0;
}
/* save data */
if(buffer && num)
memcpy(&bw_outbuf[bw_pos], buffer, num);
bw_pos += num;
return(0);
}
/* buffering_close() - writes out remaining buffered data before closing
* file.
*
*/
int buffering_close(int fd)
{
if (fd == bw_fd && bw_pos > 0) {
/* write out remaining data and clean up */
if (blocking_write(fd, bw_outbuf, bw_pos)) {
perror("write (in buffering_close)");
}
bw_fd = -1;
bw_pos = 0;
}
return(close(fd));
}
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