mirror of https://github.com/lua/lua
82 lines
1.6 KiB
C
82 lines
1.6 KiB
C
/*
|
|
** $Id: lzio.c,v 1.22 2002/10/08 18:46:08 roberto Exp roberto $
|
|
** a generic input stream interface
|
|
** See Copyright Notice in lua.h
|
|
*/
|
|
|
|
|
|
#include <string.h>
|
|
|
|
#define lzio_c
|
|
|
|
#include "lua.h"
|
|
|
|
#include "llimits.h"
|
|
#include "lmem.h"
|
|
#include "lzio.h"
|
|
|
|
|
|
int luaZ_fill (ZIO *z) {
|
|
size_t size;
|
|
const char *buff = z->reader(NULL, z->data, &size);
|
|
if (buff == NULL || size == 0) return EOZ;
|
|
z->n = size - 1;
|
|
z->p = buff;
|
|
return *(z->p++);
|
|
}
|
|
|
|
|
|
int luaZ_lookahead (ZIO *z) {
|
|
if (z->n == 0) {
|
|
int c = luaZ_fill(z);
|
|
if (c == EOZ) return c;
|
|
z->n++;
|
|
z->p--;
|
|
}
|
|
return *z->p;
|
|
}
|
|
|
|
|
|
void luaZ_init (ZIO *z, lua_Chunkreader reader, void *data, const char *name) {
|
|
z->reader = reader;
|
|
z->data = data;
|
|
z->name = name;
|
|
z->n = 0;
|
|
z->p = NULL;
|
|
}
|
|
|
|
|
|
/* --------------------------------------------------------------- read --- */
|
|
size_t luaZ_read (ZIO *z, void *b, size_t n) {
|
|
while (n) {
|
|
size_t m;
|
|
if (z->n == 0) {
|
|
if (luaZ_fill(z) == EOZ)
|
|
return n; /* return number of missing bytes */
|
|
else {
|
|
++z->n; /* filbuf removed first byte; put back it */
|
|
--z->p;
|
|
}
|
|
}
|
|
m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
|
|
memcpy(b, z->p, m);
|
|
z->n -= m;
|
|
z->p += m;
|
|
b = (char *)b + m;
|
|
n -= m;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* ------------------------------------------------------------------------ */
|
|
char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
|
|
if (n > buff->buffsize) {
|
|
if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
|
|
luaM_reallocvector(L, buff->buffer, buff->buffsize, n, char);
|
|
buff->buffsize = n;
|
|
}
|
|
return buff->buffer;
|
|
}
|
|
|
|
|