misc/liblua/lzio.c
author unc0rr
Sun, 02 Dec 2012 01:25:11 +0400
changeset 8178 8bd087478b48
parent 2812 0a24853de796
permissions -rw-r--r--
Fix QSettings problems: - Reopen file in ReadOnly mode if it was open in ReadWrite mode and is being read. This is needed for stupid QSettings which opens file in ReadWrite mode just to call readAll() on it. - Implement setSize(0)

/*
** $Id: lzio.c,v 1.31.1.1 2007/12/27 13:02:25 roberto Exp $
** a generic input stream interface
** See Copyright Notice in lua.h
*/


#include <string.h>

#define lzio_c
#define LUA_CORE

#include "lua.h"

#include "llimits.h"
#include "lmem.h"
#include "lstate.h"
#include "lzio.h"


int luaZ_fill (ZIO *z) {
  size_t size;
  lua_State *L = z->L;
  const char *buff;
  lua_unlock(L);
  buff = z->reader(L, z->data, &size);
  lua_lock(L);
  if (buff == NULL || size == 0) return EOZ;
  z->n = size - 1;
  z->p = buff;
  return char2int(*(z->p++));
}


int luaZ_lookahead (ZIO *z) {
  if (z->n == 0) {
    if (luaZ_fill(z) == EOZ)
      return EOZ;
    else {
      z->n++;  /* luaZ_fill removed first byte; put back it */
      z->p--;
    }
  }
  return char2int(*z->p);
}


void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
  z->L = L;
  z->reader = reader;
  z->data = data;
  z->n = 0;
  z->p = NULL;
}


/* --------------------------------------------------------------- read --- */
size_t luaZ_read (ZIO *z, void *b, size_t n) {
  while (n) {
    size_t m;
    if (luaZ_lookahead(z) == EOZ)
      return n;  /* return number of missing bytes */
    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;
    luaZ_resizebuffer(L, buff, n);
  }
  return buff->buffer;
}