| /* |
| ** $Id: lzio.c,v 1.10 2000/02/08 16:39:42 roberto Exp roberto $ |
| ** a generic input stream interface |
| ** See Copyright Notice in lua.h |
| */ |
| |
| |
| |
| #include <stdio.h> |
| #include <string.h> |
| |
| #include "lzio.h" |
| |
| |
| |
| /* ----------------------------------------------------- memory buffers --- */ |
| |
| static int zmfilbuf (ZIO* z) { |
| (void)z; /* to avoid warnings */ |
| return EOZ; |
| } |
| |
| |
| ZIO* zmopen (ZIO* z, const char* b, int size, const char *name) { |
| if (b==NULL) return NULL; |
| z->n = size; |
| z->p = (const unsigned char *)b; |
| z->filbuf = zmfilbuf; |
| z->u = NULL; |
| z->name = name; |
| return z; |
| } |
| |
| /* ------------------------------------------------------------ strings --- */ |
| |
| ZIO* zsopen (ZIO* z, const char* s, const char *name) { |
| if (s==NULL) return NULL; |
| return zmopen(z, s, strlen(s), name); |
| } |
| |
| /* -------------------------------------------------------------- FILEs --- */ |
| |
| static int zffilbuf (ZIO* z) { |
| int n; |
| if (feof((FILE *)z->u)) return EOZ; |
| n = fread(z->buffer, 1, ZBSIZE, (FILE *)z->u); |
| if (n==0) return EOZ; |
| z->n = n-1; |
| z->p = z->buffer; |
| return *(z->p++); |
| } |
| |
| |
| ZIO* zFopen (ZIO* z, FILE* f, const char *name) { |
| if (f==NULL) return NULL; |
| z->n = 0; |
| z->p = z->buffer; |
| z->filbuf = zffilbuf; |
| z->u = f; |
| z->name = name; |
| return z; |
| } |
| |
| |
| /* --------------------------------------------------------------- read --- */ |
| int zread (ZIO *z, void *b, int n) { |
| while (n) { |
| int m; |
| if (z->n == 0) { |
| if (z->filbuf(z) == EOZ) |
| return n; /* return number of missing bytes */ |
| zungetc(z); /* put result from `filbuf' in the buffer */ |
| } |
| 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; |
| } |