[rsync/rsync.git] / token.c

/* 
   Copyright (C) Andrew Tridgell 1996
   Copyright (C) Paul Mackerras 1996
   
   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.
*/

#include "rsync.h"
#include "zlib/zlib.h"

extern int do_compression;


/* non-compressing recv token */
static int simple_recv_token(int f,char **data)
{
	static int residue;
	static char *buf;
	int n;

	if (!buf) {
		buf = (char *)malloc(CHUNK_SIZE);
		if (!buf) out_of_memory("simple_recv_token");
	}

	if (residue == 0) {
		int i = read_int(f);
		if (i <= 0) return i;
		residue = i;
	}

	*data = buf;
	n = MIN(CHUNK_SIZE,residue);
	residue -= n;
	read_buf(f,buf,n);
	return n;
}


/* non-compressing send token */
static void simple_send_token(int f,int token,
			      struct map_struct *buf,OFF_T offset,int n)
{
	if (n > 0) {
		int l = 0;
		while (l < n) {
			int n1 = MIN(CHUNK_SIZE,n-l);
			write_int(f,n1);
			write_buf(f,map_ptr(buf,offset+l,n1),n1);
			l += n1;
		}
	}
	/* a -2 token means to send data only and no token */
	if (token != -2) {
		write_int(f,-(token+1));
	}
}


/* Flag bytes in compressed stream are encoded as follows: */
#define END_FLAG	0	/* that's all folks */
#define TOKEN_LONG	0x20	/* followed by 32-bit token number */
#define TOKENRUN_LONG	0x21	/* ditto with 16-bit run count */
#define DEFLATED_DATA	0x40	/* + 6-bit high len, then low len byte */
#define TOKEN_REL	0x80	/* + 6-bit relative token number */
#define TOKENRUN_REL	0xc0	/* ditto with 16-bit run count */

#define MAX_DATA_COUNT	16383	/* fit 14 bit count into 2 bytes with flags */

/* For coding runs of tokens */
static int last_token = -1;
static int run_start;
static int last_run_end;

/* Deflation state */
static z_stream tx_strm;

/* Output buffer */
static char *obuf;

/* Send a deflated token */
static void
send_deflated_token(int f, int token,
		    struct map_struct *buf, OFF_T offset, int nb, int toklen)
{
	int n, r;
	static int init_done, flush_pending;

	if (last_token == -1) {
		/* initialization */
		if (!init_done) {
			tx_strm.next_in = NULL;
			tx_strm.zalloc = NULL;
			tx_strm.zfree = NULL;
			if (deflateInit2(&tx_strm, Z_DEFAULT_COMPRESSION,
					 Z_DEFLATED, -15, 8,
					 Z_DEFAULT_STRATEGY) != Z_OK) {
				rprintf(FERROR, "compression init failed\n");
				exit_cleanup(RERR_STREAMIO);
			}
			if ((obuf = malloc(MAX_DATA_COUNT+2)) == NULL)
				out_of_memory("send_deflated_token");
			init_done = 1;
		} else
			deflateReset(&tx_strm);
		last_run_end = 0;
		run_start = token;
		flush_pending = 0;

	} else if (last_token == -2) {
		run_start = token;

	} else if (nb != 0 || token != last_token + 1
		   || token >= run_start + 65536) {
		/* output previous run */
		r = run_start - last_run_end;
		n = last_token - run_start;
		if (r >= 0 && r <= 63) {
			write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
		} else {
			write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
			write_int(f, run_start);
		}
		if (n != 0) {
			write_byte(f, n);
			write_byte(f, n >> 8);
		}
		last_run_end = last_token;
		run_start = token;
	}

	last_token = token;

	if (nb != 0 || flush_pending) {
		/* deflate the data starting at offset */
		int flush = Z_NO_FLUSH;
		tx_strm.avail_in = 0;
		tx_strm.avail_out = 0;
		do {
			if (tx_strm.avail_in == 0 && nb != 0) {
				/* give it some more input */
				n = MIN(nb, CHUNK_SIZE);
				tx_strm.next_in = (Bytef *)
					map_ptr(buf, offset, n);
				tx_strm.avail_in = n;
				nb -= n;
				offset += n;
			}
			if (tx_strm.avail_out == 0) {
				tx_strm.next_out = (Bytef *)(obuf + 2);
				tx_strm.avail_out = MAX_DATA_COUNT;
				if (flush != Z_NO_FLUSH) {
					/*
					 * We left the last 4 bytes in the
					 * buffer, in case they are the
					 * last 4.  Move them to the front.
					 */
					memcpy(tx_strm.next_out,
					       obuf+MAX_DATA_COUNT-2, 4);
					tx_strm.next_out += 4;
					tx_strm.avail_out -= 4;
				}
			}
			if (nb == 0 && token != -2)
				flush = Z_SYNC_FLUSH;
			r = deflate(&tx_strm, flush);
			if (r != Z_OK) {
				rprintf(FERROR, "deflate returned %d\n", r);
				exit_cleanup(RERR_STREAMIO);
			}
			if (nb == 0 || tx_strm.avail_out == 0) {
				n = MAX_DATA_COUNT - tx_strm.avail_out;
				if (flush != Z_NO_FLUSH) {
					/*
					 * We have to trim off the last 4
					 * bytes of output when flushing
					 * (they are just 0, 0, ff, ff).
					 */
					n -= 4;
				}
				if (n > 0) {
					obuf[0] = DEFLATED_DATA + (n >> 8);
					obuf[1] = n;
					write_buf(f, obuf, n+2);
				}
			}
		} while (nb != 0 || tx_strm.avail_out == 0);
		flush_pending = token == -2;
	}

	if (token == -1) {
		/* end of file - clean up */
		write_byte(f, END_FLAG);

	} else if (token != -2) {
		/* add the data in the current block to the compressor's
		   history and hash table */
		tx_strm.next_in = (Bytef *) map_ptr(buf, offset, toklen);
		tx_strm.avail_in = toklen;
		tx_strm.next_out = (Bytef *) obuf;
		tx_strm.avail_out = MAX_DATA_COUNT;
		r = deflate(&tx_strm, Z_INSERT_ONLY);
		if (r != Z_OK || tx_strm.avail_in != 0) {
			rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
				r, tx_strm.avail_in);
			exit_cleanup(RERR_STREAMIO);
		}
	}
}


/* tells us what the receiver is in the middle of doing */
static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;

/* for inflating stuff */
static z_stream rx_strm;
static char *cbuf;
static char *dbuf;

/* for decoding runs of tokens */
static int rx_token;
static int rx_run;

/* Receive a deflated token and inflate it */
static int
recv_deflated_token(int f, char **data)
{
	int n, r, flag;
	static int init_done;
	static int saved_flag;

	for (;;) {
		switch (recv_state) {
		case r_init:
			if (!init_done) {
				rx_strm.next_out = NULL;
				rx_strm.zalloc = NULL;
				rx_strm.zfree = NULL;
				if (inflateInit2(&rx_strm, -15) != Z_OK) {
					rprintf(FERROR, "inflate init failed\n");
					exit_cleanup(RERR_STREAMIO);
				}
				if ((cbuf = malloc(MAX_DATA_COUNT)) == NULL
				    || (dbuf = malloc(CHUNK_SIZE)) == NULL)
					out_of_memory("recv_deflated_token");
				init_done = 1;
			} else {
				inflateReset(&rx_strm);
			}
			recv_state = r_idle;
			rx_token = 0;
			break;

		case r_idle:
		case r_inflated:
			if (saved_flag) {
				flag = saved_flag & 0xff;
				saved_flag = 0;
			} else
				flag = read_byte(f);
			if ((flag & 0xC0) == DEFLATED_DATA) {
				n = ((flag & 0x3f) << 8) + read_byte(f);
				read_buf(f, cbuf, n);
				rx_strm.next_in = (Bytef *)cbuf;
				rx_strm.avail_in = n;
				recv_state = r_inflating;
				break;
			}
			if (recv_state == r_inflated) {
				/* check previous inflated stuff ended correctly */
				rx_strm.avail_in = 0;
				rx_strm.next_out = (Bytef *)dbuf;
				rx_strm.avail_out = CHUNK_SIZE;
				r = inflate(&rx_strm, Z_SYNC_FLUSH);
				n = CHUNK_SIZE - rx_strm.avail_out;
				/*
				 * Z_BUF_ERROR just means no progress was
				 * made, i.e. the decompressor didn't have
				 * any pending output for us.
				 */
				if (r != Z_OK && r != Z_BUF_ERROR) {
					rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
						r, n);
					exit_cleanup(RERR_STREAMIO);
				}
				if (n != 0 && r != Z_BUF_ERROR) {
					/* have to return some more data and
					   save the flag for later. */
					saved_flag = flag + 0x10000;
					*data = dbuf;
					return n;
				}
				/*
				 * At this point the decompressor should
				 * be expecting to see the 0, 0, ff, ff bytes.
				 */
				if (!inflateSyncPoint(&rx_strm)) {
					rprintf(FERROR, "decompressor lost sync!\n");
					exit_cleanup(RERR_STREAMIO);
				}
				rx_strm.avail_in = 4;
				rx_strm.next_in = (Bytef *)cbuf;
				cbuf[0] = cbuf[1] = 0;
				cbuf[2] = cbuf[3] = 0xff;
				inflate(&rx_strm, Z_SYNC_FLUSH);
				recv_state = r_idle;
			}
			if (flag == END_FLAG) {
				/* that's all folks */
				recv_state = r_init;
				return 0;
			}

			/* here we have a token of some kind */
			if (flag & TOKEN_REL) {
				rx_token += flag & 0x3f;
				flag >>= 6;
			} else
				rx_token = read_int(f);
			if (flag & 1) {
				rx_run = read_byte(f);
				rx_run += read_byte(f) << 8;
				recv_state = r_running;
			}
			return -1 - rx_token;

		case r_inflating:
			rx_strm.next_out = (Bytef *)dbuf;
			rx_strm.avail_out = CHUNK_SIZE;
			r = inflate(&rx_strm, Z_NO_FLUSH);
			n = CHUNK_SIZE - rx_strm.avail_out;
			if (r != Z_OK) {
				rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
				exit_cleanup(RERR_STREAMIO);
			}
			if (rx_strm.avail_in == 0)
				recv_state = r_inflated;
			if (n != 0) {
				*data = dbuf;
				return n;
			}
			break;

		case r_running:
			++rx_token;
			if (--rx_run == 0)
				recv_state = r_idle;
			return -1 - rx_token;
		}
	}
}

/*
 * put the data corresponding to a token that we've just returned
 * from recv_deflated_token into the decompressor's history buffer.
 */
static void see_deflate_token(char *buf, int len)
{
	int r, blklen;
	unsigned char hdr[5];

	rx_strm.avail_in = 0;
	blklen = 0;
	hdr[0] = 0;
	do {
		if (rx_strm.avail_in == 0 && len != 0) {
			if (blklen == 0) {
				/* Give it a fake stored-block header. */
				rx_strm.next_in = (Bytef *)hdr;
				rx_strm.avail_in = 5;
				blklen = len;
				if (blklen > 0xffff)
					blklen = 0xffff;
				hdr[1] = blklen;
				hdr[2] = blklen >> 8;
				hdr[3] = ~hdr[1];
				hdr[4] = ~hdr[2];
			} else {
				rx_strm.next_in = (Bytef *)buf;
				rx_strm.avail_in = blklen;
				len -= blklen;
				blklen = 0;
			}
		}
		rx_strm.next_out = (Bytef *)dbuf;
		rx_strm.avail_out = CHUNK_SIZE;
		r = inflate(&rx_strm, Z_SYNC_FLUSH);
		if (r != Z_OK) {
			rprintf(FERROR, "inflate (token) returned %d\n", r);
			exit_cleanup(RERR_STREAMIO);
		}
	} while (len || rx_strm.avail_out == 0);
}

/*
 * transmit a verbatim buffer of length n followed by a token 
 * If token == -1 then we have reached EOF 
 * If n == 0 then don't send a buffer
 */
void send_token(int f,int token,struct map_struct *buf,OFF_T offset,
		int n,int toklen)
{
	if (!do_compression) {
		simple_send_token(f,token,buf,offset,n);
	} else {
		send_deflated_token(f, token, buf, offset, n, toklen);
	}
}


/*
 * receive a token or buffer from the other end. If the reurn value is >0 then
 * it is a data buffer of that length, and *data will point at the data.
 * if the return value is -i then it represents token i-1
 * if the return value is 0 then the end has been reached
 */
int recv_token(int f,char **data)
{
	int tok;

	if (!do_compression) {
		tok = simple_recv_token(f,data);
	} else {
		tok = recv_deflated_token(f, data);
	}
	return tok;
}

/*
 * look at the data corresponding to a token, if necessary
 */
void see_token(char *data, int toklen)
{
	if (do_compression)
		see_deflate_token(data, toklen);
}
Commit	Line	Data
70d794dc AT	1	/*
	2	Copyright (C) Andrew Tridgell 1996
	3	Copyright (C) Paul Mackerras 1996
	4
	5	This program is free software; you can redistribute it and/or modify
	6	it under the terms of the GNU General Public License as published by
	7	the Free Software Foundation; either version 2 of the License, or
	8	(at your option) any later version.
	9
	10	This program is distributed in the hope that it will be useful,
	11	but WITHOUT ANY WARRANTY; without even the implied warranty of
	12	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	13	GNU General Public License for more details.
	14
	15	You should have received a copy of the GNU General Public License
	16	along with this program; if not, write to the Free Software
	17	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
	18	*/
	19
	20	#include "rsync.h"
5914bf15	21	#include "zlib/zlib.h"
70d794dc AT	22
	23	extern int do_compression;
	24
	25
	26	/* non-compressing recv token */
	27	static int simple_recv_token(int f,char **data)
	28	{
c5eb3650 AT	29	static int residue;
	30	static char *buf;
	31	int n;
70d794dc	32
c5eb3650 AT	33	if (!buf) {
	34	buf = (char *)malloc(CHUNK_SIZE);
	35	if (!buf) out_of_memory("simple_recv_token");
	36	}
70d794dc	37
c5eb3650 AT	38	if (residue == 0) {
	39	int i = read_int(f);
	40	if (i <= 0) return i;
	41	residue = i;
	42	}
70d794dc	43
c5eb3650 AT	44	*data = buf;
	45	n = MIN(CHUNK_SIZE,residue);
	46	residue -= n;
	47	read_buf(f,buf,n);
	48	return n;
70d794dc AT	49	}
	50
	51
	52	/* non-compressing send token */
c6e7fcb4	53	static void simple_send_token(int f,int token,
45f133b9	54	struct map_struct *buf,OFF_T offset,int n)
70d794dc	55	{
c5eb3650 AT	56	if (n > 0) {
	57	int l = 0;
	58	while (l < n) {
	59	int n1 = MIN(CHUNK_SIZE,n-l);
	60	write_int(f,n1);
	61	write_buf(f,map_ptr(buf,offset+l,n1),n1);
	62	l += n1;
	63	}
	64	}
45f133b9 AT	65	/* a -2 token means to send data only and no token */
	66	if (token != -2) {
	67	write_int(f,-(token+1));
	68	}
70d794dc AT	69	}
	70
	71
861c20b4 PM	72	/* Flag bytes in compressed stream are encoded as follows: */
	73	#define END_FLAG 0 /* that's all folks */
	74	#define TOKEN_LONG 0x20 /* followed by 32-bit token number */
	75	#define TOKENRUN_LONG 0x21 /* ditto with 16-bit run count */
	76	#define DEFLATED_DATA 0x40 /* + 6-bit high len, then low len byte */
	77	#define TOKEN_REL 0x80 /* + 6-bit relative token number */
	78	#define TOKENRUN_REL 0xc0 /* ditto with 16-bit run count */
	79
	80	#define MAX_DATA_COUNT 16383 /* fit 14 bit count into 2 bytes with flags */
	81
	82	/* For coding runs of tokens */
	83	static int last_token = -1;
	84	static int run_start;
	85	static int last_run_end;
	86
	87	/* Deflation state */
	88	static z_stream tx_strm;
	89
	90	/* Output buffer */
3a6a366f	91	static char *obuf;
861c20b4 PM	92
	93	/* Send a deflated token */
	94	static void
	95	send_deflated_token(int f, int token,
45f133b9	96	struct map_struct *buf, OFF_T offset, int nb, int toklen)
861c20b4	97	{
5914bf15 PM	98	int n, r;
	99	static int init_done, flush_pending;
	100
	101	if (last_token == -1) {
	102	/* initialization */
	103	if (!init_done) {
	104	tx_strm.next_in = NULL;
	105	tx_strm.zalloc = NULL;
	106	tx_strm.zfree = NULL;
	107	if (deflateInit2(&tx_strm, Z_DEFAULT_COMPRESSION,
	108	Z_DEFLATED, -15, 8,
	109	Z_DEFAULT_STRATEGY) != Z_OK) {
	110	rprintf(FERROR, "compression init failed\n");
65417579	111	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	112	}
	113	if ((obuf = malloc(MAX_DATA_COUNT+2)) == NULL)
	114	out_of_memory("send_deflated_token");
	115	init_done = 1;
	116	} else
	117	deflateReset(&tx_strm);
	118	last_run_end = 0;
	119	run_start = token;
	120	flush_pending = 0;
	121
	122	} else if (last_token == -2) {
	123	run_start = token;
	124
	125	} else if (nb != 0 \|\| token != last_token + 1
	126	\|\| token >= run_start + 65536) {
	127	/* output previous run */
	128	r = run_start - last_run_end;
	129	n = last_token - run_start;
	130	if (r >= 0 && r <= 63) {
	131	write_byte(f, (n==0? TOKEN_REL: TOKENRUN_REL) + r);
	132	} else {
	133	write_byte(f, (n==0? TOKEN_LONG: TOKENRUN_LONG));
	134	write_int(f, run_start);
	135	}
	136	if (n != 0) {
	137	write_byte(f, n);
	138	write_byte(f, n >> 8);
	139	}
	140	last_run_end = last_token;
	141	run_start = token;
861c20b4	142	}
5914bf15 PM	143
	144	last_token = token;
	145
	146	if (nb != 0 \|\| flush_pending) {
	147	/* deflate the data starting at offset */
	148	int flush = Z_NO_FLUSH;
	149	tx_strm.avail_in = 0;
	150	tx_strm.avail_out = 0;
	151	do {
	152	if (tx_strm.avail_in == 0 && nb != 0) {
	153	/* give it some more input */
	154	n = MIN(nb, CHUNK_SIZE);
	155	tx_strm.next_in = (Bytef *)
	156	map_ptr(buf, offset, n);
	157	tx_strm.avail_in = n;
	158	nb -= n;
	159	offset += n;
	160	}
	161	if (tx_strm.avail_out == 0) {
	162	tx_strm.next_out = (Bytef *)(obuf + 2);
	163	tx_strm.avail_out = MAX_DATA_COUNT;
	164	if (flush != Z_NO_FLUSH) {
	165	/*
	166	* We left the last 4 bytes in the
	167	* buffer, in case they are the
	168	* last 4. Move them to the front.
	169	*/
	170	memcpy(tx_strm.next_out,
	171	obuf+MAX_DATA_COUNT-2, 4);
	172	tx_strm.next_out += 4;
	173	tx_strm.avail_out -= 4;
	174	}
	175	}
	176	if (nb == 0 && token != -2)
	177	flush = Z_SYNC_FLUSH;
	178	r = deflate(&tx_strm, flush);
	179	if (r != Z_OK) {
	180	rprintf(FERROR, "deflate returned %d\n", r);
65417579	181	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	182	}
	183	if (nb == 0 \|\| tx_strm.avail_out == 0) {
	184	n = MAX_DATA_COUNT - tx_strm.avail_out;
	185	if (flush != Z_NO_FLUSH) {
	186	/*
	187	* We have to trim off the last 4
	188	* bytes of output when flushing
	189	* (they are just 0, 0, ff, ff).
	190	*/
	191	n -= 4;
	192	}
	193	if (n > 0) {
	194	obuf[0] = DEFLATED_DATA + (n >> 8);
	195	obuf[1] = n;
	196	write_buf(f, obuf, n+2);
	197	}
	198	}
	199	} while (nb != 0 \|\| tx_strm.avail_out == 0);
	200	flush_pending = token == -2;
861c20b4	201	}
861c20b4	202
5914bf15 PM	203	if (token == -1) {
	204	/* end of file - clean up */
	205	write_byte(f, END_FLAG);
861c20b4	206
5914bf15 PM	207	} else if (token != -2) {
	208	/* add the data in the current block to the compressor's
	209	history and hash table */
	210	tx_strm.next_in = (Bytef *) map_ptr(buf, offset, toklen);
	211	tx_strm.avail_in = toklen;
	212	tx_strm.next_out = (Bytef *) obuf;
861c20b4	213	tx_strm.avail_out = MAX_DATA_COUNT;
5914bf15 PM	214	r = deflate(&tx_strm, Z_INSERT_ONLY);
	215	if (r != Z_OK \|\| tx_strm.avail_in != 0) {
	216	rprintf(FERROR, "deflate on token returned %d (%d bytes left)\n",
	217	r, tx_strm.avail_in);
65417579	218	exit_cleanup(RERR_STREAMIO);
861c20b4	219	}
861c20b4	220	}
861c20b4 PM	221	}
	222
	223
	224	/* tells us what the receiver is in the middle of doing */
	225	static enum { r_init, r_idle, r_running, r_inflating, r_inflated } recv_state;
70d794dc	226
861c20b4 PM	227	/* for inflating stuff */
	228	static z_stream rx_strm;
	229	static char *cbuf;
	230	static char *dbuf;
	231
	232	/* for decoding runs of tokens */
	233	static int rx_token;
	234	static int rx_run;
	235
	236	/* Receive a deflated token and inflate it */
	237	static int
	238	recv_deflated_token(int f, char **data)
	239	{
5914bf15 PM	240	int n, r, flag;
	241	static int init_done;
	242	static int saved_flag;
	243
	244	for (;;) {
	245	switch (recv_state) {
	246	case r_init:
	247	if (!init_done) {
	248	rx_strm.next_out = NULL;
	249	rx_strm.zalloc = NULL;
	250	rx_strm.zfree = NULL;
	251	if (inflateInit2(&rx_strm, -15) != Z_OK) {
	252	rprintf(FERROR, "inflate init failed\n");
65417579	253	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	254	}
	255	if ((cbuf = malloc(MAX_DATA_COUNT)) == NULL
	256	\|\| (dbuf = malloc(CHUNK_SIZE)) == NULL)
	257	out_of_memory("recv_deflated_token");
	258	init_done = 1;
	259	} else {
	260	inflateReset(&rx_strm);
	261	}
b8d4524b	262	recv_state = r_idle;
5914bf15 PM	263	rx_token = 0;
	264	break;
	265
	266	case r_idle:
	267	case r_inflated:
	268	if (saved_flag) {
	269	flag = saved_flag & 0xff;
	270	saved_flag = 0;
	271	} else
	272	flag = read_byte(f);
	273	if ((flag & 0xC0) == DEFLATED_DATA) {
	274	n = ((flag & 0x3f) << 8) + read_byte(f);
	275	read_buf(f, cbuf, n);
	276	rx_strm.next_in = (Bytef *)cbuf;
	277	rx_strm.avail_in = n;
	278	recv_state = r_inflating;
	279	break;
	280	}
	281	if (recv_state == r_inflated) {
	282	/* check previous inflated stuff ended correctly */
	283	rx_strm.avail_in = 0;
	284	rx_strm.next_out = (Bytef *)dbuf;
	285	rx_strm.avail_out = CHUNK_SIZE;
	286	r = inflate(&rx_strm, Z_SYNC_FLUSH);
	287	n = CHUNK_SIZE - rx_strm.avail_out;
	288	/*
	289	* Z_BUF_ERROR just means no progress was
	290	* made, i.e. the decompressor didn't have
	291	* any pending output for us.
	292	*/
	293	if (r != Z_OK && r != Z_BUF_ERROR) {
	294	rprintf(FERROR, "inflate flush returned %d (%d bytes)\n",
	295	r, n);
65417579	296	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	297	}
	298	if (n != 0 && r != Z_BUF_ERROR) {
	299	/* have to return some more data and
	300	save the flag for later. */
	301	saved_flag = flag + 0x10000;
	302	*data = dbuf;
	303	return n;
	304	}
	305	/*
	306	* At this point the decompressor should
	307	* be expecting to see the 0, 0, ff, ff bytes.
	308	*/
	309	if (!inflateSyncPoint(&rx_strm)) {
	310	rprintf(FERROR, "decompressor lost sync!\n");
65417579	311	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	312	}
	313	rx_strm.avail_in = 4;
	314	rx_strm.next_in = (Bytef *)cbuf;
	315	cbuf[0] = cbuf[1] = 0;
	316	cbuf[2] = cbuf[3] = 0xff;
	317	inflate(&rx_strm, Z_SYNC_FLUSH);
	318	recv_state = r_idle;
	319	}
	320	if (flag == END_FLAG) {
	321	/* that's all folks */
	322	recv_state = r_init;
	323	return 0;
	324	}
	325
	326	/* here we have a token of some kind */
	327	if (flag & TOKEN_REL) {
	328	rx_token += flag & 0x3f;
	329	flag >>= 6;
	330	} else
	331	rx_token = read_int(f);
	332	if (flag & 1) {
	333	rx_run = read_byte(f);
	334	rx_run += read_byte(f) << 8;
	335	recv_state = r_running;
	336	}
	337	return -1 - rx_token;
	338
	339	case r_inflating:
	340	rx_strm.next_out = (Bytef *)dbuf;
	341	rx_strm.avail_out = CHUNK_SIZE;
	342	r = inflate(&rx_strm, Z_NO_FLUSH);
	343	n = CHUNK_SIZE - rx_strm.avail_out;
	344	if (r != Z_OK) {
	345	rprintf(FERROR, "inflate returned %d (%d bytes)\n", r, n);
65417579	346	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	347	}
	348	if (rx_strm.avail_in == 0)
	349	recv_state = r_inflated;
	350	if (n != 0) {
	351	*data = dbuf;
	352	return n;
	353	}
	354	break;
	355
	356	case r_running:
	357	++rx_token;
	358	if (--rx_run == 0)
	359	recv_state = r_idle;
	360	return -1 - rx_token;
b8d4524b	361	}
861c20b4	362	}
861c20b4 PM	363	}
	364
	365	/*
	366	* put the data corresponding to a token that we've just returned
	367	* from recv_deflated_token into the decompressor's history buffer.
	368	*/
6e4fb64e	369	static void see_deflate_token(char *buf, int len)
861c20b4	370	{
5914bf15 PM	371	int r, blklen;
	372	unsigned char hdr[5];
	373
	374	rx_strm.avail_in = 0;
	375	blklen = 0;
	376	hdr[0] = 0;
	377	do {
	378	if (rx_strm.avail_in == 0 && len != 0) {
	379	if (blklen == 0) {
	380	/* Give it a fake stored-block header. */
	381	rx_strm.next_in = (Bytef *)hdr;
	382	rx_strm.avail_in = 5;
	383	blklen = len;
	384	if (blklen > 0xffff)
	385	blklen = 0xffff;
	386	hdr[1] = blklen;
	387	hdr[2] = blklen >> 8;
	388	hdr[3] = ~hdr[1];
	389	hdr[4] = ~hdr[2];
	390	} else {
	391	rx_strm.next_in = (Bytef *)buf;
	392	rx_strm.avail_in = blklen;
	393	len -= blklen;
	394	blklen = 0;
	395	}
	396	}
	397	rx_strm.next_out = (Bytef *)dbuf;
	398	rx_strm.avail_out = CHUNK_SIZE;
	399	r = inflate(&rx_strm, Z_SYNC_FLUSH);
	400	if (r != Z_OK) {
	401	rprintf(FERROR, "inflate (token) returned %d\n", r);
65417579	402	exit_cleanup(RERR_STREAMIO);
5914bf15 PM	403	}
5914bf15 PM	404	} while (len \|\| rx_strm.avail_out == 0);
861c20b4	405	}
70d794dc AT	406
	407	/*
	408	* transmit a verbatim buffer of length n followed by a token
	409	* If token == -1 then we have reached EOF
	410	* If n == 0 then don't send a buffer
70d794dc	411	*/
45f133b9	412	void send_token(int f,int token,struct map_struct *buf,OFF_T offset,
9e31c482	413	int n,int toklen)
70d794dc	414	{
5914bf15 PM	415	if (!do_compression) {
	416	simple_send_token(f,token,buf,offset,n);
	417	} else {
	418	send_deflated_token(f, token, buf, offset, n, toklen);
	419	}
70d794dc AT	420	}
	421
	422
	423	/*
	424	* receive a token or buffer from the other end. If the reurn value is >0 then
	425	* it is a data buffer of that length, and *data will point at the data.
	426	* if the return value is -i then it represents token i-1
	427	* if the return value is 0 then the end has been reached
	428	*/
	429	int recv_token(int f,char **data)
	430	{
5914bf15 PM	431	int tok;
	432
	433	if (!do_compression) {
	434	tok = simple_recv_token(f,data);
	435	} else {
	436	tok = recv_deflated_token(f, data);
	437	}
	438	return tok;
861c20b4 PM	439	}
	440
	441	/*
	442	* look at the data corresponding to a token, if necessary
	443	*/
	444	void see_token(char *data, int toklen)
	445	{
5914bf15 PM	446	if (do_compression)
5914bf15 PM	447	see_deflate_token(data, toklen);
70d794dc	448	}