162 lines
3.5 KiB
C
162 lines
3.5 KiB
C
/*
|
|
*
|
|
* buffer.c
|
|
*
|
|
* Author: Tatu Ylonen <ylo@cs.hut.fi>
|
|
*
|
|
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
|
|
* All rights reserved
|
|
*
|
|
* Created: Sat Mar 18 04:15:33 1995 ylo
|
|
*
|
|
* Functions for manipulating fifo buffers (that can grow if needed).
|
|
*
|
|
*/
|
|
|
|
#include "includes.h"
|
|
RCSID("$Id: buffer.c,v 1.6 2000/04/14 10:30:30 markus Exp $");
|
|
|
|
#include "xmalloc.h"
|
|
#include "buffer.h"
|
|
#include "ssh.h"
|
|
|
|
/* Initializes the buffer structure. */
|
|
|
|
void
|
|
buffer_init(Buffer *buffer)
|
|
{
|
|
buffer->alloc = 4096;
|
|
buffer->buf = xmalloc(buffer->alloc);
|
|
buffer->offset = 0;
|
|
buffer->end = 0;
|
|
}
|
|
|
|
/* Frees any memory used for the buffer. */
|
|
|
|
void
|
|
buffer_free(Buffer *buffer)
|
|
{
|
|
memset(buffer->buf, 0, buffer->alloc);
|
|
xfree(buffer->buf);
|
|
}
|
|
|
|
/*
|
|
* Clears any data from the buffer, making it empty. This does not actually
|
|
* zero the memory.
|
|
*/
|
|
|
|
void
|
|
buffer_clear(Buffer *buffer)
|
|
{
|
|
buffer->offset = 0;
|
|
buffer->end = 0;
|
|
}
|
|
|
|
/* Appends data to the buffer, expanding it if necessary. */
|
|
|
|
void
|
|
buffer_append(Buffer *buffer, const char *data, unsigned int len)
|
|
{
|
|
char *cp;
|
|
buffer_append_space(buffer, &cp, len);
|
|
memcpy(cp, data, len);
|
|
}
|
|
|
|
/*
|
|
* Appends space to the buffer, expanding the buffer if necessary. This does
|
|
* not actually copy the data into the buffer, but instead returns a pointer
|
|
* to the allocated region.
|
|
*/
|
|
|
|
void
|
|
buffer_append_space(Buffer *buffer, char **datap, unsigned int len)
|
|
{
|
|
/* If the buffer is empty, start using it from the beginning. */
|
|
if (buffer->offset == buffer->end) {
|
|
buffer->offset = 0;
|
|
buffer->end = 0;
|
|
}
|
|
restart:
|
|
/* If there is enough space to store all data, store it now. */
|
|
if (buffer->end + len < buffer->alloc) {
|
|
*datap = buffer->buf + buffer->end;
|
|
buffer->end += len;
|
|
return;
|
|
}
|
|
/*
|
|
* If the buffer is quite empty, but all data is at the end, move the
|
|
* data to the beginning and retry.
|
|
*/
|
|
if (buffer->offset > buffer->alloc / 2) {
|
|
memmove(buffer->buf, buffer->buf + buffer->offset,
|
|
buffer->end - buffer->offset);
|
|
buffer->end -= buffer->offset;
|
|
buffer->offset = 0;
|
|
goto restart;
|
|
}
|
|
/* Increase the size of the buffer and retry. */
|
|
buffer->alloc += len + 32768;
|
|
buffer->buf = xrealloc(buffer->buf, buffer->alloc);
|
|
goto restart;
|
|
}
|
|
|
|
/* Returns the number of bytes of data in the buffer. */
|
|
|
|
unsigned int
|
|
buffer_len(Buffer *buffer)
|
|
{
|
|
return buffer->end - buffer->offset;
|
|
}
|
|
|
|
/* Gets data from the beginning of the buffer. */
|
|
|
|
void
|
|
buffer_get(Buffer *buffer, char *buf, unsigned int len)
|
|
{
|
|
if (len > buffer->end - buffer->offset)
|
|
fatal("buffer_get: trying to get more bytes than in buffer");
|
|
memcpy(buf, buffer->buf + buffer->offset, len);
|
|
buffer->offset += len;
|
|
}
|
|
|
|
/* Consumes the given number of bytes from the beginning of the buffer. */
|
|
|
|
void
|
|
buffer_consume(Buffer *buffer, unsigned int bytes)
|
|
{
|
|
if (bytes > buffer->end - buffer->offset)
|
|
fatal("buffer_consume: trying to get more bytes than in buffer");
|
|
buffer->offset += bytes;
|
|
}
|
|
|
|
/* Consumes the given number of bytes from the end of the buffer. */
|
|
|
|
void
|
|
buffer_consume_end(Buffer *buffer, unsigned int bytes)
|
|
{
|
|
if (bytes > buffer->end - buffer->offset)
|
|
fatal("buffer_consume_end: trying to get more bytes than in buffer");
|
|
buffer->end -= bytes;
|
|
}
|
|
|
|
/* Returns a pointer to the first used byte in the buffer. */
|
|
|
|
char *
|
|
buffer_ptr(Buffer *buffer)
|
|
{
|
|
return buffer->buf + buffer->offset;
|
|
}
|
|
|
|
/* Dumps the contents of the buffer to stderr. */
|
|
|
|
void
|
|
buffer_dump(Buffer *buffer)
|
|
{
|
|
int i;
|
|
unsigned char *ucp = (unsigned char *) buffer->buf;
|
|
|
|
for (i = buffer->offset; i < buffer->end; i++)
|
|
fprintf(stderr, " %02x", ucp[i]);
|
|
fprintf(stderr, "\n");
|
|
}
|