torrent-stats/linebuffer.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <stdarg.h>

#include "linebuffer.h"

#define MIN(a,b) (((a) < (b)) ? (a) : (b))

struct linebuffer * create_linebuffer(int size)
{
	struct linebuffer *buf = malloc(sizeof(struct linebuffer));
	if (buf == NULL)
		return NULL;

	buf->size = size;
	buf->data = malloc(buf->size);
	if (buf->data == NULL) {
		free(buf);
		return NULL;
	}

	buf->pos = 0;
	return buf;
}

void linebuffer_free(struct linebuffer *buf)
{
	free(buf->data);
	free(buf);
}

int linebuffer_clear(struct linebuffer *buf)
{
	int oldpos = buf->pos;
	buf->pos = 0;
	return oldpos;
}

int linebuffer_put(struct linebuffer *buf, const char *src, unsigned int size)
{
	int len = MIN(buf->size - buf->pos, size);
	memcpy(buf->data + buf->pos, src, len);
	return len;
}

int linebuffer_readfd(struct linebuffer *buf, int fd)
{
	int len = read(fd, buf->data + buf->pos, buf->size - buf->pos);
	if (len <= 0)
		return -1;

	buf->pos += len;
	return len;
}

int linebuffer_parsefd(struct linebuffer *buf, int fd)
{
	char tmp[32];
	int len = read(fd, tmp, sizeof(tmp));
	if (len <= 0)
		return -1;

	int i;
	for (i = 0; i < len; i++) {
		/* "understand" backspace */
		if (tmp[i] == 0x08 && buf->pos > 0) {
			buf->pos--;

		/* copy */
		} else if (tmp[i] >= ' ' || tmp[i] == '\n') {
			*(buf->data + buf->pos++) = tmp[i];
		}

		if (buf->pos > buf->size)
			return -1;
	}
	return 0;
}

int linebuffer_writefd(struct linebuffer *buf, int fd)
{
	int len = write(fd, buf->data, buf->pos);
	if (len <= 0)
		return -1;

	/* TODO: now assuming everything is written */
	buf->pos = 0;
	return len;
}

int linebuffer_printf(struct linebuffer *buf, const char *fmt, ...)
{
	va_list az;
	va_start(az, fmt);
	int len = vsnprintf(buf->data + buf->pos, buf->size - buf->pos, fmt, az);
	va_end(az);

	if (len < 0 || len >= (buf->size - buf->pos))
		return -1;

	buf->pos += len;
	return len;
}

char * linebuffer_getline(struct linebuffer *buf, int *len)
{
	buf->newline = memchr(buf->data, '\n', buf->pos);
	if (buf->newline == NULL)
		return NULL;

	*(buf->newline) = '\0';

	if (len != NULL)
		*len = buf->newline - buf->data;

	return buf->data;
}

int linebuffer_freeline(struct linebuffer *buf)
{
	buf->pos -= (buf->newline - buf->data) +1;
	memmove(buf->data, buf->newline +1, buf->pos);
	buf->newline = NULL;
	return buf->pos;
}