+++ /dev/null
-/* $Id$ $Revision$ */
-/* vim:set shiftwidth=4 ts=8: */
-
-/*************************************************************************
- * Copyright (c) 2011 AT&T Intellectual Property
- * All rights reserved. This program and the accompanying materials
- * are made available under the terms of the Eclipse Public License v1.0
- * which accompanies this distribution, and is available at
- * http://www.eclipse.org/legal/epl-v10.html
- *
- * Contributors: See CVS logs. Details at http://www.graphviz.org/
- *************************************************************************/
-
-#include "sfhdr.h"
-
-/* Move data from one stream to another.
-** This code is written so that it'll work even in the presence
-** of stacking streams, pool, and discipline.
-** If you must change it, be gentle.
-**
-** Written by Kiem-Phong Vo.
-*/
-#define MAX_SSIZE ((ssize_t)((~((size_t)0)) >> 1))
-
-/**
- * @param fr moving data from this stream
- * @param fw moving data to this stream
- * @param n number of bytes/records to move. <0 for unbounded move
- * @param rc record separator
- */
-Sfoff_t sfmove(Sfio_t * fr, Sfio_t * fw, Sfoff_t n, reg int rc)
-{
- reg uchar *cp, *next;
- reg ssize_t r, w;
- reg uchar *endb;
- reg int direct;
- Sfoff_t n_move;
- uchar *rbuf = NIL(uchar *);
- ssize_t rsize = 0;
-
- SFMTXSTART(fr, (Sfoff_t) 0);
- if (fw)
- SFMTXLOCK(fw);
-
- for (n_move = 0; n != 0;) { /* get the streams into the right mode */
- if (fr->mode != SF_READ && _sfmode(fr, SF_READ, 0) < 0)
- goto done;
-
- SFLOCK(fr, 0);
-
- /* flush the write buffer as necessary to make room */
- if (fw) {
- if (fw->mode != SF_WRITE && _sfmode(fw, SF_WRITE, 0) < 0)
- break;
- SFLOCK(fw, 0);
- if (fw->next >= fw->endb ||
- (fw->next > fw->data && fr->extent < 0 &&
- (fw->extent < 0 || (fw->flags & SF_SHARE))))
- if (SFFLSBUF(fw, -1) < 0)
- break;
- }
-
- /* about to move all, set map to a large amount */
- if (n < 0 && (fr->bits & SF_MMAP) && !(fr->bits & SF_MVSIZE)) {
- SFMVSET(fr);
-
- if (rc < 0) /* data will be accessed sequentially */
- fr->bits |= SF_SEQUENTIAL;
- }
-
- /* try reading a block of data */
- direct = 0;
- if ((r = fr->endb - (next = fr->next)) <= 0) { /* amount of data remained to be read */
- if ((w = n > MAX_SSIZE ? MAX_SSIZE : (ssize_t) n) < 0) {
- if (fr->extent < 0)
- w = fr->data == fr->tiny ? SF_GRAIN : fr->size;
- else if ((fr->extent - fr->here) > SF_NMAP * SF_PAGE)
- w = SF_NMAP * SF_PAGE;
- else
- w = (ssize_t) (fr->extent - fr->here);
- }
-
- /* use a decent buffer for data transfer but make sure
- that if we overread, the left over can be retrieved
- */
- if (!(fr->flags & SF_STRING) && !(fr->bits & SF_MMAP) &&
- (n < 0 || fr->extent >= 0)) {
- reg ssize_t maxw = 4 * (_Sfpage > 0 ? _Sfpage : SF_PAGE);
-
- /* direct transfer to a seekable write stream */
- if (fw && fw->extent >= 0 && w <= (fw->endb - fw->next)) {
- w = fw->endb - (next = fw->next);
- direct = SF_WRITE;
- } else if (w > fr->size && maxw > fr->size) { /* making our own buffer */
- if (w >= maxw)
- w = maxw;
- else
- w = ((w + fr->size - 1) / fr->size) * fr->size;
- if (rsize <= 0 && (rbuf = (uchar *) malloc(w)))
- rsize = w;
- if (rbuf) {
- next = rbuf;
- w = rsize;
- direct = SF_STRING;
- }
- }
- }
-
- if (!direct) { /* make sure we don't read too far ahead */
- if (n > 0 && fr->extent < 0 && (fr->flags & SF_SHARE)) {
- if (rc >= 0) { /* try peeking a large buffer */
- fr->mode |= SF_RV;
- if ((r = SFFILBUF(fr, -1)) > 0)
- goto done_filbuf;
- else if (n > 1 && !fr->disc) {
- r = sfpkrd(fr->file,
- (void *) fr->data,
- fr->size, rc, -1, (int) (-n));
- if (r <= 0)
- goto one_r;
- fr->next = fr->data;
- fr->endb = fr->endr = fr->next + r;
- goto done_filbuf;
- } else { /* get a single record */
- one_r:fr->getr = rc;
- fr->mode |= SF_RC;
- r = -1;
- }
- } else if ((Sfoff_t) (r = fr->size) > n)
- r = (ssize_t) n;
- } else
- r = -1;
- if ((r = SFFILBUF(fr, r)) <= 0)
- break;
- done_filbuf:
- next = fr->next;
- } else { /* actual amount to be read */
- if (rc < 0 && n > 0 && n < w)
- w = (ssize_t) n;
-
- if ((r = SFRD(fr, next, w, fr->disc)) > 0)
- fr->next = fr->endb = fr->endr = fr->data;
- else if (r == 0)
- break; /* eof */
- else
- goto again; /* popped stack */
- }
- }
-
- /* compute the extent of data to be moved */
- endb = next + r;
- if (rc < 0) {
- if (n > 0) {
- if (r > n)
- r = (ssize_t) n;
- n -= r;
- }
- n_move += r;
- cp = next + r;
- } else { /* count records */
- reg int rdwr = (fr->flags & SF_MALLOC) ||
- (fr->bits & (SF_BOTH | SF_MMAP));
- if (rdwr) {
- w = endb[-1];
- endb[-1] = rc;
- } else
- w = 0;
- for (cp = next; cp < endb;) { /* find the line extent */
- if (rdwr)
- while (*cp++ != rc);
- else
- while (r-- && *cp++ != rc);
- if (cp < endb || w == rc) {
- n_move += 1;
- if (n > 0 && (n -= 1) == 0)
- break;
- }
- }
- if (rdwr)
- endb[-1] = w;
- r = cp - next;
- if (fr->mode & SF_PKRD) { /* advance the read point by proper amount */
- fr->mode &= ~SF_PKRD;
- (void) read(fr->file, (void *) next, r);
- fr->here += r;
- if (!direct)
- fr->endb = cp;
- else
- endb = cp;
- }
- }
-
- if (!direct)
- fr->next += r;
- else if ((w = endb - cp) > 0) { /* move left-over to read stream */
- if (w > fr->size)
- w = fr->size;
- memcpy((void *) fr->data, (void *) cp, w);
- fr->endb = fr->data + w;
- if ((w = endb - (cp + w)) > 0)
- (void) SFSK(fr, (Sfoff_t) (-w), SEEK_CUR, fr->disc);
- }
-
- if (fw) {
- if (direct == SF_WRITE)
- fw->next += r;
- else if (r <= (fw->endb - fw->next)) {
- memcpy((void *) fw->next, (void *) next, r);
- fw->next += r;
- } else if ((w = SFWRITE(fw, (void *) next, r)) != r) { /* a write error happened */
- if (w > 0) {
- r -= w;
- if (rc < 0)
- n_move -= r;
- }
- if (fr->extent >= 0)
- (void) SFSEEK(fr, (Sfoff_t) (-r), 1);
- break;
- }
- }
-
- again:
- SFOPEN(fr, 0);
- if (fw)
- SFOPEN(fw, 0);
- }
-
- done:
- if (n < 0 && (fr->bits & SF_MMAP) && (fr->bits & SF_MVSIZE)) { /* back to normal access mode */
- SFMVUNSET(fr);
- if ((fr->bits & SF_SEQUENTIAL) && (fr->data))
- SFMMSEQOFF(fr, fr->data, fr->endb - fr->data);
- fr->bits &= ~SF_SEQUENTIAL;
- }
-
- if (rbuf)
- free(rbuf);
-
- SFOPEN(fr, 0);
- if (fw) {
- SFOPEN(fw, 0);
- SFMTXUNLOCK(fw);
- }
-
- SFMTXRETURN(fr, n_move);
-}
projects / graphviz / commitdiff