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Rev | Author | Line No. | Line |
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5205 | clevermous | 1 | /* |
2 | ** $Id: lzio.c,v 1.34 2011/07/15 12:35:32 roberto Exp $ |
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3 | ** a generic input stream interface |
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4 | ** See Copyright Notice in lua.h |
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5 | */ |
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6 | |||
7 | |||
8 | #include |
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9 | |||
10 | #define lzio_c |
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11 | #define LUA_CORE |
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12 | |||
13 | #include "lua.h" |
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14 | |||
15 | #include "llimits.h" |
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16 | #include "lmem.h" |
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17 | #include "lstate.h" |
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18 | #include "lzio.h" |
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19 | |||
20 | |||
21 | int luaZ_fill (ZIO *z) { |
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22 | size_t size; |
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23 | lua_State *L = z->L; |
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24 | const char *buff; |
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25 | lua_unlock(L); |
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26 | buff = z->reader(L, z->data, &size); |
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27 | lua_lock(L); |
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28 | if (buff == NULL || size == 0) |
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29 | return EOZ; |
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30 | z->n = size - 1; /* discount char being returned */ |
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31 | z->p = buff; |
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32 | return cast_uchar(*(z->p++)); |
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33 | } |
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34 | |||
35 | |||
36 | void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) { |
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37 | z->L = L; |
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38 | z->reader = reader; |
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39 | z->data = data; |
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40 | z->n = 0; |
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41 | z->p = NULL; |
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42 | } |
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43 | |||
44 | |||
45 | /* --------------------------------------------------------------- read --- */ |
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46 | size_t luaZ_read (ZIO *z, void *b, size_t n) { |
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47 | while (n) { |
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48 | size_t m; |
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49 | if (z->n == 0) { /* no bytes in buffer? */ |
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50 | if (luaZ_fill(z) == EOZ) /* try to read more */ |
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51 | return n; /* no more input; return number of missing bytes */ |
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52 | else { |
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53 | z->n++; /* luaZ_fill consumed first byte; put it back */ |
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54 | z->p--; |
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55 | } |
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56 | } |
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57 | m = (n <= z->n) ? n : z->n; /* min. between n and z->n */ |
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58 | memcpy(b, z->p, m); |
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59 | z->n -= m; |
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60 | z->p += m; |
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61 | b = (char *)b + m; |
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62 | n -= m; |
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63 | } |
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64 | return 0; |
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65 | } |
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66 | |||
67 | /* ------------------------------------------------------------------------ */ |
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68 | char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) { |
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69 | if (n > buff->buffsize) { |
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70 | if (n < LUA_MINBUFFER) n = LUA_MINBUFFER; |
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71 | luaZ_resizebuffer(L, buff, n); |
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72 | } |
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73 | return buff->buffer; |
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74 | }>=> |
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75 |