ossp-pkg/var/tokenbuf.c
#include "internal.h"
#define VAR_INITIAL_BUFFER_SIZE 1
void init_tokenbuf(tokenbuf* buf)
{
buf->begin = buf->end = NULL;
buf->buffer_size = 0;
}
void move_tokenbuf(tokenbuf* src, tokenbuf* dst)
{
dst->begin = src->begin;
dst->end = src->end;
dst->buffer_size = src->buffer_size;
init_tokenbuf(src);
}
int assign_to_tokenbuf(tokenbuf* buf, const char* data, size_t len)
{
char* p = malloc(len+1);
if (p)
{
memcpy(p, data, len);
buf->begin = p;
buf->end = p + len;
buf->buffer_size = len + 1;
*((char*)(buf->end)) = '\0';
return 1;
}
else
return 0;
}
int append_to_tokenbuf(tokenbuf* output, const char* data, size_t len)
{
char* new_buffer;
size_t new_size;
/* Is the tokenbuffer initialized at all? If not, allocate a
standard-sized buffer to begin with. */
if (output->begin == NULL)
{
if ((output->begin = output->end = malloc(VAR_INITIAL_BUFFER_SIZE)) == NULL)
return 0;
else
output->buffer_size = VAR_INITIAL_BUFFER_SIZE;
}
/* Does the token contain text, but no buffer has been allocated
yet? */
if (output->buffer_size == 0)
{
/* Check whether data borders to output. If, we can append
simly by increasing the end pointer. */
if (output->end == data)
{
output->end += len;
return 1;
}
/* OK, so copy the contents of output into an allocated buffer
so that we can append that way. */
else
{
char* tmp = malloc(output->end - output->begin + len + 1);
if (!tmp)
return 0;
memcpy(tmp, output->begin, output->end - output->begin);
output->buffer_size = output->end - output->begin;
output->begin = tmp;
output->end = tmp + output->buffer_size;
output->buffer_size += len + 1;
}
}
/* Does the token fit into the current buffer? If not, realloc a
larger buffer that fits. */
if ((output->buffer_size - (output->end - output->begin)) <= len)
{
new_size = output->buffer_size;
do
{
new_size *= 2;
}
while ((new_size - (output->end - output->begin)) <= len);
new_buffer = realloc((char*)output->begin, new_size);
if (new_buffer == NULL)
return 0;
output->end = new_buffer + (output->end - output->begin);
output->begin = new_buffer;
output->buffer_size = new_size;
}
/* Append the data at the end of the current buffer. */
memcpy((char*)output->end, data, len);
output->end += len;
*((char*)output->end) = '\0';
return 1;
}
void free_tokenbuf(tokenbuf* buf)
{
if (buf->begin != NULL && buf->buffer_size > 0)
free((char*)buf->begin);
buf->begin = buf->end = NULL;
buf->buffer_size = 0;
}
