annotate src/lua/lzio.c @ 467:ac0ed5c1a1c4

working on drums.
author Robert McIntyre <rlm@mit.edu>
date Fri, 04 May 2012 05:17:18 -0500
parents 27763b933818
children
rev   line source
rlm@1 1 /*
rlm@1 2 ** $Id: lzio.c,v 1.31.1.1 2007/12/27 13:02:25 roberto Exp $
rlm@1 3 ** a generic input stream interface
rlm@1 4 ** See Copyright Notice in lua.h
rlm@1 5 */
rlm@1 6
rlm@1 7
rlm@1 8 #include <string.h>
rlm@1 9
rlm@1 10 #define lzio_c
rlm@1 11 #define LUA_CORE
rlm@1 12
rlm@1 13 #include "lua.h"
rlm@1 14
rlm@1 15 #include "llimits.h"
rlm@1 16 #include "lmem.h"
rlm@1 17 #include "lstate.h"
rlm@1 18 #include "lzio.h"
rlm@1 19
rlm@1 20
rlm@1 21 int luaZ_fill (ZIO *z) {
rlm@1 22 size_t size;
rlm@1 23 lua_State *L = z->L;
rlm@1 24 const char *buff;
rlm@1 25 lua_unlock(L);
rlm@1 26 buff = z->reader(L, z->data, &size);
rlm@1 27 lua_lock(L);
rlm@1 28 if (buff == NULL || size == 0) return EOZ;
rlm@1 29 z->n = size - 1;
rlm@1 30 z->p = buff;
rlm@1 31 return char2int(*(z->p++));
rlm@1 32 }
rlm@1 33
rlm@1 34
rlm@1 35 int luaZ_lookahead (ZIO *z) {
rlm@1 36 if (z->n == 0) {
rlm@1 37 if (luaZ_fill(z) == EOZ)
rlm@1 38 return EOZ;
rlm@1 39 else {
rlm@1 40 z->n++; /* luaZ_fill removed first byte; put back it */
rlm@1 41 z->p--;
rlm@1 42 }
rlm@1 43 }
rlm@1 44 return char2int(*z->p);
rlm@1 45 }
rlm@1 46
rlm@1 47
rlm@1 48 void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) {
rlm@1 49 z->L = L;
rlm@1 50 z->reader = reader;
rlm@1 51 z->data = data;
rlm@1 52 z->n = 0;
rlm@1 53 z->p = NULL;
rlm@1 54 }
rlm@1 55
rlm@1 56
rlm@1 57 /* --------------------------------------------------------------- read --- */
rlm@1 58 size_t luaZ_read (ZIO *z, void *b, size_t n) {
rlm@1 59 while (n) {
rlm@1 60 size_t m;
rlm@1 61 if (luaZ_lookahead(z) == EOZ)
rlm@1 62 return n; /* return number of missing bytes */
rlm@1 63 m = (n <= z->n) ? n : z->n; /* min. between n and z->n */
rlm@1 64 memcpy(b, z->p, m);
rlm@1 65 z->n -= m;
rlm@1 66 z->p += m;
rlm@1 67 b = (char *)b + m;
rlm@1 68 n -= m;
rlm@1 69 }
rlm@1 70 return 0;
rlm@1 71 }
rlm@1 72
rlm@1 73 /* ------------------------------------------------------------------------ */
rlm@1 74 char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) {
rlm@1 75 if (n > buff->buffsize) {
rlm@1 76 if (n < LUA_MINBUFFER) n = LUA_MINBUFFER;
rlm@1 77 luaZ_resizebuffer(L, buff, n);
rlm@1 78 }
rlm@1 79 return buff->buffer;
rlm@1 80 }
rlm@1 81
rlm@1 82