rev |
line source |
jbe@121
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1 #include <lua.h>
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jbe@121
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2 #include <lauxlib.h>
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jbe@122
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3 #include <stdlib.h>
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jbe@121
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4 #include <string.h>
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5
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jbe@142
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6 #define JSON_MAXDEPTH 100
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jbe@142
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7
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jbe@138
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8 #define JSON_REGENT static char
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jbe@138
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9 #define JSON_REGREF void *
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10
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jbe@138
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11 JSON_REGENT json_nullmark;
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jbe@138
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12 JSON_REGENT json_shadowtbl;
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jbe@138
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13 JSON_REGENT json_unknownmt;
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jbe@138
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14 JSON_REGENT json_objectmt;
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jbe@138
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15 JSON_REGENT json_arraymt;
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16
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jbe@138
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17 #define json_regfetch(L, x) (lua_pushlightuserdata((L), &(x)), lua_rawget((L), LUA_REGISTRYINDEX))
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18
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19 #define json_regstore(L, x) (lua_pushlightuserdata(L, &(x)), lua_pushvalue(L, -2), lua_rawset(L, LUA_REGISTRYINDEX));
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jbe@138
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20
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jbe@136
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21 // marks a table as JSON object or JSON array:
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jbe@136
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22 // (returns its modified argument or a new table if argument is nil)
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jbe@138
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23 static int json_mark(lua_State *L, JSON_REGREF mt) {
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jbe@136
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24 // if argument is nil, then create new table:
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jbe@136
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25 if (lua_isnoneornil(L, 1)) {
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jbe@136
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26 lua_settop(L, 0);
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jbe@136
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27 lua_newtable(L);
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jbe@136
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28 // skip testing of existing shadow table:
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jbe@136
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29 goto json_object_create_shadow_table;
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jbe@136
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30 }
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jbe@138
|
31 // check if shadow table already exists:
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jbe@138
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32 json_regfetch(L, json_shadowtbl);
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jbe@136
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33 lua_pushvalue(L, 1);
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jbe@138
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34 lua_rawget(L, -2);
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jbe@136
|
35 if (lua_isnil(L, -1)) {
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jbe@136
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36 json_object_create_shadow_table:
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jbe@136
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37 // set shadow table:
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jbe@136
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38 lua_pushvalue(L, 1);
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jbe@136
|
39 lua_newtable(L);
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jbe@138
|
40 lua_rawset(L, -4);
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jbe@136
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41 }
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jbe@138
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42 // discard everything but table to return:
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jbe@138
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43 lua_settop(L, 1);
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jbe@136
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44 // set metatable:
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jbe@138
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45 json_regfetch(L, mt);
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jbe@136
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46 lua_setmetatable(L, 1);
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jbe@138
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47 // return table:
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jbe@136
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48 return 1;
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jbe@136
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49 }
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50
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jbe@136
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51 // marks a table as JSON object:
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jbe@136
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52 // (returns its modified argument or a new table if argument is nil)
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53 static int json_object(lua_State *L) {
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jbe@138
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54 return json_mark(L, &json_objectmt);
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jbe@136
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55 }
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56
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jbe@136
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57 // marks a table as JSON array:
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jbe@136
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58 // (returns its modified argument or a new table if argument is nil)
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jbe@136
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59 static int json_array(lua_State *L) {
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jbe@138
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60 return json_mark(L, &json_arraymt);
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jbe@136
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61 }
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62
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jbe@124
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63 #define JSON_STATE_VALUE 0
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jbe@124
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64 #define JSON_STATE_OBJECT_KEY 1
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jbe@124
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65 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
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jbe@124
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66 #define JSON_STATE_OBJECT_VALUE 3
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jbe@124
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67 #define JSON_STATE_OBJECT_SEPARATOR 4
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jbe@124
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68 #define JSON_STATE_ARRAY_VALUE 5
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jbe@124
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69 #define JSON_STATE_ARRAY_SEPARATOR 6
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jbe@124
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70 #define JSON_STATE_END 7
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71
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jbe@138
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72 #define json_import_objectmt_idx 2
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jbe@138
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73 #define json_import_arraymt_idx 3
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jbe@138
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74 #define json_import_shadowtbl_idx 4
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jbe@138
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75 #define json_import_nullmark_idx 5
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76
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jbe@136
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77 // decodes a JSON document:
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jbe@121
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78 static int json_import(lua_State *L) {
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79 const char *str; // string to parse
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80 size_t total; // total length of string to parse
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81 size_t pos = 0; // current position in string to parse
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82 size_t level = 0; // nested levels of objects/arrays currently being processed
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jbe@136
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83 int mode = JSON_STATE_VALUE; // state of parser
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jbe@136
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84 char c; // variable to store a single character to be processed
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85 luaL_Buffer luabuf; // Lua buffer to decode (possibly escaped) strings
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86 char *cbuf; // C buffer to decode (possibly escaped) strings
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87 size_t writepos; // write position of decoded strings in C buffer
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jbe@138
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88 // limit stack to 1 element:
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jbe@138
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89 lua_settop(L, 1);
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jbe@138
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90 // push json_objectmt on stack position 2:
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91 json_regfetch(L, json_objectmt);
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jbe@138
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92 // push json_arraymt on stack position 3:
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jbe@138
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93 json_regfetch(L, json_arraymt);
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jbe@138
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94 // push json_shadowtbl on stack position 4:
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jbe@138
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95 json_regfetch(L, json_shadowtbl);
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jbe@138
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96 // push json_nullmark on stack position 5:
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jbe@138
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97 json_regfetch(L, json_nullmark);
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jbe@136
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98 // require string as first argument:
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99 str = luaL_checklstring(L, 1, &total);
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jbe@136
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100 // if string contains a NULL byte, this is a syntax error
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jbe@136
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101 if (strlen(str) != total) goto json_import_syntax_error;
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jbe@136
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102 // main loop of parser:
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103 json_import_loop:
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104 // skip whitespace and store next character in variable 'c':
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105 while (c = str[pos], c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\f') pos++;
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jbe@136
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106 // switch statement to handle certain (single) characters:
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jbe@121
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107 switch (c) {
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jbe@136
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108 // handle end of JSON document:
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jbe@121
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109 case 0:
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jbe@136
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110 // if end of JSON document was expected, then return top element of stack as result:
|
jbe@124
|
111 if (mode == JSON_STATE_END) return 1;
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jbe@136
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112 // otherwise, the JSON document was malformed:
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jbe@121
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113 json_import_unexpected_eof:
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jbe@121
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114 lua_pushnil(L);
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jbe@121
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115 if (level == 0) lua_pushliteral(L, "Empty string");
|
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|
116 else lua_pushliteral(L, "Unexpected end of JSON document");
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jbe@121
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117 return 2;
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jbe@136
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118 // new JSON object:
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jbe@121
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119 case '{':
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jbe@136
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120 // if a JSON object is not expected here, then return an error:
|
jbe@124
|
121 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
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jbe@121
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122 goto json_import_syntax_error;
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jbe@136
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123 // create JSON object on stack:
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jbe@136
|
124 lua_newtable(L);
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jbe@136
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125 // set metatable of JSON object:
|
jbe@138
|
126 lua_pushvalue(L, json_import_objectmt_idx);
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jbe@125
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127 lua_setmetatable(L, -2);
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jbe@136
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128 // create internal shadow table on stack:
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jbe@136
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129 lua_newtable(L);
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jbe@138
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130 // register internal shadow table (and cleanup stack afterwards):
|
jbe@123
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131 lua_pushvalue(L, -2);
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jbe@123
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132 lua_pushvalue(L, -2);
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jbe@138
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133 lua_rawset(L, json_import_shadowtbl_idx);
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jbe@136
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134 // expect object key (or end of object) and continue with loop:
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jbe@136
|
135 mode = JSON_STATE_OBJECT_KEY;
|
jbe@142
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136 goto json_import_open;
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jbe@136
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137 // new JSON array:
|
jbe@121
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138 case '[':
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jbe@136
|
139 // if a JSON array is not expected here, then return an error:
|
jbe@124
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140 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
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jbe@121
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141 goto json_import_syntax_error;
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jbe@136
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142 // create JSON array on stack:
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jbe@136
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143 lua_newtable(L);
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jbe@136
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144 // set metatable of JSON array:
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jbe@138
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145 lua_pushvalue(L, json_import_arraymt_idx);
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jbe@125
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146 lua_setmetatable(L, -2);
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jbe@136
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147 // create internal shadow table on stack:
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jbe@136
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148 lua_newtable(L);
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jbe@138
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149 // register internal shadow table (and cleanup stack afterwards):
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jbe@123
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150 lua_pushvalue(L, -2);
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jbe@123
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151 lua_pushvalue(L, -2);
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jbe@138
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152 lua_rawset(L, json_import_shadowtbl_idx);
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jbe@140
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153 // add nil as key (needed to keep stack balance) and as magic to detect arrays:
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jbe@140
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154 lua_pushnil(L);
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jbe@142
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155 // expect array value (or end of array) and continue with loop:
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jbe@142
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156 mode = JSON_STATE_ARRAY_VALUE;
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jbe@142
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157 // continue with common code for opening JSON object and JSON array:
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jbe@142
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158 // commn code for opening JSON object or JSON array:
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jbe@142
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159 json_import_open:
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jbe@142
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160 // limit nested levels:
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jbe@142
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161 if (level >= JSON_MAXDEPTH) {
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jbe@142
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162 lua_pushnil(L);
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jbe@142
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163 lua_pushliteral(L, "Too many nested JSON levels");
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jbe@142
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164 return 2;
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jbe@142
|
165 }
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jbe@142
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166 // additional buffer overflow protection:
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jbe@142
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167 if (!lua_checkstack(L, LUA_MINSTACK))
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jbe@142
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168 return luaL_error(L, "Caught stack overflow in JSON import function (too many nested levels and stack size too small)");
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jbe@136
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169 // increment level:
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jbe@121
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170 level++;
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jbe@142
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171 // consume input character:
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jbe@142
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172 pos++;
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jbe@121
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173 goto json_import_loop;
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jbe@136
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174 // end of JSON object:
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jbe@121
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175 case '}':
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jbe@136
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176 // if end of JSON object is not expected here, then return an error:
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jbe@124
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177 if (mode != JSON_STATE_OBJECT_KEY && mode != JSON_STATE_OBJECT_SEPARATOR)
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jbe@121
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178 goto json_import_syntax_error;
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jbe@136
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179 // jump to common code for end of JSON object and JSON array:
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jbe@121
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180 goto json_import_close;
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jbe@136
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181 // end of JSON array:
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jbe@121
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182 case ']':
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jbe@136
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183 // if end of JSON array is not expected here, then return an error:
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jbe@124
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184 if (mode != JSON_STATE_ARRAY_VALUE && mode != JSON_STATE_ARRAY_SEPARATOR)
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jbe@121
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185 goto json_import_syntax_error;
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jbe@140
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186 // pop nil key/magic:
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jbe@140
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187 lua_pop(L, 1);
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jbe@136
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188 // continue with common code for end of JSON object and JSON array:
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jbe@136
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189 // common code for end of JSON object or JSON array:
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jbe@121
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190 json_import_close:
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jbe@136
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191 // consume input character:
|
jbe@121
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192 pos++;
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jbe@136
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193 // pop shadow table:
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jbe@136
|
194 lua_pop(L, 1);
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jbe@136
|
195 // check if nested:
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jbe@121
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196 if (--level) {
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jbe@136
|
197 // if nested, then check if outer(!) structure is an array or object:
|
jbe@140
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198 if (lua_isnil(L, -2)) {
|
jbe@136
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199 // select array value processing:
|
jbe@124
|
200 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
201 } else {
|
jbe@136
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202 // select object value processing:
|
jbe@124
|
203 mode = JSON_STATE_OBJECT_VALUE;
|
jbe@121
|
204 }
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jbe@136
|
205 // store value in outer structure:
|
jbe@121
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206 goto json_import_process_value;
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jbe@121
|
207 }
|
jbe@136
|
208 // if not nested, then expect end of JSON document and continue with loop:
|
jbe@136
|
209 mode = JSON_STATE_END;
|
jbe@121
|
210 goto json_import_loop;
|
jbe@136
|
211 // key terminator:
|
jbe@121
|
212 case ':':
|
jbe@136
|
213 // if key terminator is not expected here, then return an error:
|
jbe@124
|
214 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
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jbe@121
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215 goto json_import_syntax_error;
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jbe@136
|
216 // consume input character:
|
jbe@121
|
217 pos++;
|
jbe@136
|
218 // set state of parser and continue with loop:
|
jbe@124
|
219 mode = JSON_STATE_OBJECT_VALUE;
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jbe@121
|
220 goto json_import_loop;
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jbe@136
|
221 // value terminator (NOTE: trailing comma at end of value or key-value list is tolerated by this parser)
|
jbe@121
|
222 case ',':
|
jbe@136
|
223 // change parser state accordingly:
|
jbe@124
|
224 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
|
jbe@124
|
225 mode = JSON_STATE_OBJECT_KEY;
|
jbe@124
|
226 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
|
jbe@124
|
227 mode = JSON_STATE_ARRAY_VALUE;
|
jbe@121
|
228 } else {
|
jbe@136
|
229 // if value terminator is not expected here, then return an error:
|
jbe@136
|
230 goto json_import_syntax_error;
|
jbe@121
|
231 }
|
jbe@136
|
232 // consume input character:
|
jbe@121
|
233 pos++;
|
jbe@136
|
234 // continue with loop:
|
jbe@121
|
235 goto json_import_loop;
|
jbe@136
|
236 // string literal:
|
jbe@121
|
237 case '"':
|
jbe@136
|
238 // prepare buffer to decode string (with maximum possible length) and set write position to zero:
|
jbe@121
|
239 cbuf = luaL_buffinitsize(L, &luabuf, total-pos);
|
jbe@121
|
240 writepos = 0;
|
jbe@136
|
241 // consume quote character:
|
jbe@121
|
242 pos++;
|
jbe@136
|
243 // read next character until encountering end quote:
|
jbe@121
|
244 while ((c = str[pos++]) != '"') {
|
jbe@121
|
245 if (c == 0) {
|
jbe@136
|
246 // handle unexpected end-of-string:
|
jbe@121
|
247 goto json_import_unexpected_eof;
|
jbe@121
|
248 } else if (c < 32 || c == 127) {
|
jbe@136
|
249 // do not allow ASCII control characters:
|
jbe@136
|
250 // NOTE: illegal UTF-8 sequences and extended control characters are not sanitized
|
jbe@136
|
251 // by this parser to allow different encodings than Unicode
|
jbe@121
|
252 lua_pushnil(L);
|
jbe@121
|
253 lua_pushliteral(L, "Unexpected control character in JSON string");
|
jbe@121
|
254 return 2;
|
jbe@121
|
255 } else if (c == '\\') {
|
jbe@136
|
256 // read next char after backslash escape:
|
jbe@121
|
257 c = str[pos++];
|
jbe@121
|
258 switch (c) {
|
jbe@136
|
259 // unexpected end-of-string:
|
jbe@121
|
260 case 0:
|
jbe@121
|
261 goto json_import_unexpected_eof;
|
jbe@136
|
262 // unescaping of quotation mark, slash, and backslash:
|
jbe@121
|
263 case '"':
|
jbe@121
|
264 case '/':
|
jbe@121
|
265 case '\\':
|
jbe@121
|
266 cbuf[writepos++] = c;
|
jbe@121
|
267 break;
|
jbe@136
|
268 // unescaping of backspace:
|
jbe@121
|
269 case 'b':
|
jbe@121
|
270 cbuf[writepos++] = '\b';
|
jbe@121
|
271 break;
|
jbe@136
|
272 // unescaping of form-feed:
|
jbe@121
|
273 case 'f':
|
jbe@121
|
274 cbuf[writepos++] = '\f';
|
jbe@121
|
275 break;
|
jbe@136
|
276 // unescaping of new-line:
|
jbe@121
|
277 case 'n':
|
jbe@121
|
278 cbuf[writepos++] = '\n';
|
jbe@121
|
279 break;
|
jbe@136
|
280 // unescaping of carriage-return:
|
jbe@121
|
281 case 'r':
|
jbe@121
|
282 cbuf[writepos++] = '\r';
|
jbe@121
|
283 break;
|
jbe@136
|
284 // unescaping of tabulator:
|
jbe@121
|
285 case 't':
|
jbe@121
|
286 cbuf[writepos++] = '\t';
|
jbe@121
|
287 break;
|
jbe@136
|
288 // unescaping of UTF-16 characters
|
jbe@121
|
289 case 'u':
|
jbe@121
|
290 lua_pushnil(L);
|
jbe@121
|
291 lua_pushliteral(L, "JSON unicode escape sequences are not implemented yet"); // TODO
|
jbe@121
|
292 return 2;
|
jbe@136
|
293 // unexpected escape sequence:
|
jbe@121
|
294 default:
|
jbe@121
|
295 lua_pushnil(L);
|
jbe@121
|
296 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
|
jbe@121
|
297 return 2;
|
jbe@121
|
298 }
|
jbe@121
|
299 } else {
|
jbe@136
|
300 // normal character:
|
jbe@121
|
301 cbuf[writepos++] = c;
|
jbe@121
|
302 }
|
jbe@121
|
303 }
|
jbe@136
|
304 // process buffer to Lua string:
|
jbe@121
|
305 luaL_pushresultsize(&luabuf, writepos);
|
jbe@136
|
306 // continue with processing of decoded string:
|
jbe@121
|
307 goto json_import_process_value;
|
jbe@121
|
308 }
|
jbe@136
|
309 // process values whose type is is not deducible from a single character:
|
jbe@136
|
310 if ((c >= '0' && c <= '9') || c == '-' || c == '+') {
|
jbe@136
|
311 // numbers:
|
jbe@122
|
312 char *endptr;
|
jbe@122
|
313 double numval;
|
jbe@122
|
314 numval = strtod(str+pos, &endptr);
|
jbe@122
|
315 if (endptr == str+pos) goto json_import_syntax_error;
|
jbe@122
|
316 pos += endptr - (str+pos);
|
jbe@122
|
317 lua_pushnumber(L, numval);
|
jbe@122
|
318 } else if (!strncmp(str+pos, "true", 4)) {
|
jbe@136
|
319 // consume 4 input characters for "true":
|
jbe@121
|
320 pos += 4;
|
jbe@136
|
321 // put Lua true value on stack:
|
jbe@136
|
322 lua_pushboolean(L, 1);
|
jbe@121
|
323 } else if (!strncmp(str+pos, "false", 5)) {
|
jbe@136
|
324 // consume 5 input characters for "false":
|
jbe@121
|
325 pos += 5;
|
jbe@136
|
326 // put Lua false value on stack:
|
jbe@136
|
327 lua_pushboolean(L, 0);
|
jbe@121
|
328 } else if (!strncmp(str+pos, "null", 4)) {
|
jbe@136
|
329 // consume 4 input characters for "null":
|
jbe@136
|
330 pos += 4;
|
jbe@136
|
331 // put special null-marker on stack:
|
jbe@138
|
332 lua_pushvalue(L, json_import_nullmark_idx);
|
jbe@121
|
333 } else {
|
jbe@136
|
334 // all other cases are a syntax error:
|
jbe@121
|
335 goto json_import_syntax_error;
|
jbe@121
|
336 }
|
jbe@136
|
337 // process a decoded value or key value pair (expected on top of Lua stack):
|
jbe@136
|
338 json_import_process_value:
|
jbe@121
|
339 switch (mode) {
|
jbe@136
|
340 // an object key has been read:
|
jbe@124
|
341 case JSON_STATE_OBJECT_KEY:
|
jbe@136
|
342 // if an object key is not a string, then this is a syntax error:
|
jbe@121
|
343 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
|
jbe@136
|
344 // expect key terminator and continue with loop:
|
jbe@124
|
345 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
|
jbe@121
|
346 goto json_import_loop;
|
jbe@136
|
347 // a key value pair has been read:
|
jbe@124
|
348 case JSON_STATE_OBJECT_VALUE:
|
jbe@136
|
349 // store key value pair in outer shadow table:
|
jbe@130
|
350 lua_rawset(L, -3);
|
jbe@136
|
351 // expect value terminator (or end of object) and continue with loop:
|
jbe@124
|
352 mode = JSON_STATE_OBJECT_SEPARATOR;
|
jbe@121
|
353 goto json_import_loop;
|
jbe@136
|
354 // an array value has been read:
|
jbe@124
|
355 case JSON_STATE_ARRAY_VALUE:
|
jbe@136
|
356 // store value in outer shadow table:
|
jbe@140
|
357 lua_rawseti(L, -3, lua_rawlen(L, -3) + 1);
|
jbe@136
|
358 // expect value terminator (or end of object) and continue with loop:
|
jbe@124
|
359 mode = JSON_STATE_ARRAY_SEPARATOR;
|
jbe@121
|
360 goto json_import_loop;
|
jbe@136
|
361 // a single value has been read:
|
jbe@124
|
362 case JSON_STATE_VALUE:
|
jbe@136
|
363 // leave value on top of stack, expect end of JSON document, and continue with loop:
|
jbe@124
|
364 mode = JSON_STATE_END;
|
jbe@121
|
365 goto json_import_loop;
|
jbe@121
|
366 }
|
jbe@136
|
367 // syntax error handling (only reachable by goto statement):
|
jbe@136
|
368 json_import_syntax_error:
|
jbe@121
|
369 lua_pushnil(L);
|
jbe@121
|
370 lua_pushliteral(L, "Syntax error in JSON document");
|
jbe@121
|
371 return 2;
|
jbe@121
|
372 }
|
jbe@121
|
373
|
jbe@138
|
374 #define json_path_shadowtbl_idx 1
|
jbe@138
|
375 #define json_path_nullmark_idx 2
|
jbe@138
|
376 #define json_path_idxshift 2
|
jbe@138
|
377
|
jbe@137
|
378 // gets a value or its type from a JSON document (first argument)
|
jbe@137
|
379 // optionally using a path (variable number of keys after first argument):
|
jbe@137
|
380 static int json_path(lua_State *L, int type_mode) {
|
jbe@138
|
381 int stacktop;
|
jbe@138
|
382 int idx = 2 + json_path_idxshift;
|
jbe@138
|
383 // insert json_shadowtbl on stack at position 1:
|
jbe@138
|
384 json_regfetch(L, json_shadowtbl);
|
jbe@138
|
385 lua_insert(L, 1);
|
jbe@138
|
386 // insert json_nullmark on stack at position 2:
|
jbe@138
|
387 json_regfetch(L, json_nullmark);
|
jbe@138
|
388 lua_insert(L, 2);
|
jbe@137
|
389 // store number of arguments:
|
jbe@138
|
390 stacktop = lua_gettop(L);
|
jbe@137
|
391 // follow path, starting with first argument as "current value":
|
jbe@138
|
392 lua_pushvalue(L, 1 + json_path_idxshift);
|
jbe@137
|
393 // process each "path key":
|
jbe@138
|
394 while (idx <= stacktop) {
|
jbe@137
|
395 // if "current value" is nil, then the path cannot be walked and nil is returned:
|
jbe@137
|
396 if (lua_isnil(L, -1)) return 1;
|
jbe@137
|
397 // try to get shadow table of "current value":
|
jbe@130
|
398 lua_pushvalue(L, -1);
|
jbe@138
|
399 lua_rawget(L, json_path_shadowtbl_idx);
|
jbe@126
|
400 if (lua_isnil(L, -1)) {
|
jbe@137
|
401 // if no shadow table is found,
|
jbe@137
|
402 // drop nil from stack:
|
jbe@126
|
403 lua_pop(L, 1);
|
jbe@130
|
404 if (lua_type(L, -1) == LUA_TTABLE) {
|
jbe@137
|
405 // if "current value" is a table,
|
jbe@137
|
406 // get "next value" using the "path key":
|
jbe@130
|
407 lua_pushvalue(L, idx++);
|
jbe@130
|
408 lua_gettable(L, -2);
|
jbe@130
|
409 } else {
|
jbe@137
|
410 // if "current value" is not a table,
|
jbe@137
|
411 // then the path cannot be walked and nil is returned:
|
jbe@130
|
412 lua_pushnil(L);
|
jbe@137
|
413 return 1;
|
jbe@130
|
414 }
|
jbe@130
|
415 } else {
|
jbe@137
|
416 // if a shadow table is found,
|
jbe@137
|
417 // set "current value" to its shadow table:
|
jbe@130
|
418 lua_replace(L, -2);
|
jbe@137
|
419 // get "next value" using the "path key":
|
jbe@130
|
420 lua_pushvalue(L, idx++);
|
jbe@130
|
421 lua_rawget(L, -2);
|
jbe@126
|
422 }
|
jbe@137
|
423 // the "next value" replaces the "current value":
|
jbe@130
|
424 lua_replace(L, -2);
|
jbe@126
|
425 }
|
jbe@137
|
426 if (!type_mode) {
|
jbe@137
|
427 // if a value (and not its type) was requested,
|
jbe@137
|
428 // check if value is the null-marker, and store nil on top of Lua stack in that case:
|
jbe@138
|
429 if (lua_rawequal(L, -1, json_path_nullmark_idx)) lua_pushnil(L);
|
jbe@137
|
430 } else {
|
jbe@137
|
431 // if the type was requested,
|
jbe@137
|
432 // check if value is the null-marker:
|
jbe@138
|
433 if (lua_rawequal(L, -1, json_path_nullmark_idx)) {
|
jbe@137
|
434 // if yes, store string "null" on top of Lua stack:
|
jbe@130
|
435 lua_pushliteral(L, "null");
|
jbe@137
|
436 } else {
|
jbe@137
|
437 // otherwise,
|
jbe@138
|
438 // check if metatable indicates "object" or "array":
|
jbe@138
|
439 if (lua_getmetatable(L, -1)) {
|
jbe@138
|
440 json_regfetch(L, json_objectmt);
|
jbe@138
|
441 if (lua_rawequal(L, -2, -1)) {
|
jbe@138
|
442 // return string "object":
|
jbe@138
|
443 lua_pushliteral(L, "object");
|
jbe@138
|
444 return 1;
|
jbe@138
|
445 }
|
jbe@138
|
446 json_regfetch(L, json_arraymt);
|
jbe@138
|
447 if (lua_rawequal(L, -3, -1)) {
|
jbe@138
|
448 // return string "array":
|
jbe@138
|
449 lua_pushliteral(L, "array");
|
jbe@138
|
450 return 1;
|
jbe@138
|
451 }
|
jbe@138
|
452 lua_pop(L, 3);
|
jbe@138
|
453 }
|
jbe@138
|
454 // otherwise, get the Lua type:
|
jbe@138
|
455 lua_pushstring(L, lua_typename(L, lua_type(L, -1)));
|
jbe@126
|
456 }
|
jbe@126
|
457 }
|
jbe@137
|
458 // return the top most value on the Lua stack:
|
jbe@137
|
459 return 1;
|
jbe@130
|
460 }
|
jbe@130
|
461
|
jbe@137
|
462 // gets a value from a JSON document (first argument)
|
jbe@137
|
463 // optionally using a path (variable number of keys after first argument):
|
jbe@130
|
464 static int json_get(lua_State *L) {
|
jbe@137
|
465 return json_path(L, 0);
|
jbe@130
|
466 }
|
jbe@130
|
467
|
jbe@137
|
468 // gets a value's type from a JSON document (first argument)
|
jbe@137
|
469 // optionally using a path (variable number of keys after first argument):
|
jbe@130
|
470 static int json_type(lua_State *L) {
|
jbe@137
|
471 return json_path(L, 1);
|
jbe@130
|
472 }
|
jbe@130
|
473
|
jbe@137
|
474 // checks if a value in a JSON document (first argument) is null:
|
jbe@130
|
475 static int json_isnull(lua_State *L) {
|
jbe@137
|
476 const char *jsontype;
|
jbe@138
|
477 lua_pushcfunction(L, json_type);
|
jbe@137
|
478 lua_insert(L, 1);
|
jbe@137
|
479 lua_call(L, lua_gettop(L) - 1, 1);
|
jbe@137
|
480 jsontype = lua_tostring(L, -1);
|
jbe@137
|
481 if (jsontype && !strcmp(jsontype, "null")) lua_pushboolean(L, 1);
|
jbe@137
|
482 else lua_pushboolean(L, 0);
|
jbe@137
|
483 return 1;
|
jbe@130
|
484 }
|
jbe@130
|
485
|
jbe@138
|
486 #define json_setnull_unknownmt_idx 3
|
jbe@138
|
487 #define json_setnull_objectmt_idx 4
|
jbe@138
|
488 #define json_setnull_arraymt_idx 5
|
jbe@138
|
489 #define json_setnull_shadowtbl_idx 6
|
jbe@138
|
490
|
jbe@131
|
491 static int json_setnull(lua_State *L) {
|
jbe@138
|
492 // truncate stack to two elements:
|
jbe@131
|
493 lua_settop(L, 2);
|
jbe@138
|
494 // push json_unknownmt to stack position 3:
|
jbe@138
|
495 json_regfetch(L, json_unknownmt);
|
jbe@138
|
496 // push json_objectmt to stack position 4:
|
jbe@138
|
497 json_regfetch(L, json_objectmt);
|
jbe@138
|
498 // push json_arraymt to stack position 5:
|
jbe@138
|
499 json_regfetch(L, json_arraymt);
|
jbe@138
|
500 // push json_shadowtbl to stack position 6:
|
jbe@138
|
501 json_regfetch(L, json_shadowtbl);
|
jbe@138
|
502 //
|
jbe@138
|
503 lua_getmetatable(L, 1);
|
jbe@138
|
504 if (
|
jbe@138
|
505 !lua_rawequal(L, -1, json_setnull_unknownmt_idx) &&
|
jbe@138
|
506 !lua_rawequal(L, -1, json_setnull_objectmt_idx) &&
|
jbe@138
|
507 !lua_rawequal(L, -1, json_setnull_arraymt_idx)
|
jbe@138
|
508 ) {
|
jbe@138
|
509 lua_pushvalue(L, json_setnull_unknownmt_idx);
|
jbe@138
|
510 lua_setmetatable(L, 1);
|
jbe@138
|
511 }
|
jbe@131
|
512 lua_pushvalue(L, 1);
|
jbe@138
|
513 lua_rawget(L, json_setnull_shadowtbl_idx);
|
jbe@131
|
514 if (lua_isnil(L, -1)) {
|
jbe@131
|
515 lua_newtable(L);
|
jbe@131
|
516 lua_pushvalue(L, 1);
|
jbe@131
|
517 lua_pushvalue(L, -2);
|
jbe@138
|
518 lua_rawset(L, json_setnull_shadowtbl_idx);
|
jbe@131
|
519 }
|
jbe@131
|
520 lua_pushvalue(L, 2);
|
jbe@138
|
521 json_regfetch(L, json_nullmark);
|
jbe@131
|
522 lua_rawset(L, -3);
|
jbe@131
|
523 return 0;
|
jbe@131
|
524 }
|
jbe@131
|
525
|
jbe@130
|
526 static int json_len(lua_State *L) {
|
jbe@130
|
527 lua_settop(L, 1);
|
jbe@138
|
528 json_regfetch(L, json_shadowtbl);
|
jbe@130
|
529 lua_pushvalue(L, 1);
|
jbe@138
|
530 lua_rawget(L, -2);
|
jbe@138
|
531 lua_pushinteger(L, lua_rawlen(L, lua_isnil(L, -1) ? 1 : -1));
|
jbe@123
|
532 return 1;
|
jbe@123
|
533 }
|
jbe@123
|
534
|
jbe@141
|
535 #define json_index_nullmark_idx 3
|
jbe@141
|
536 #define json_index_shadowtbl_idx 4
|
jbe@141
|
537
|
jbe@130
|
538 static int json_index(lua_State *L) {
|
jbe@130
|
539 lua_settop(L, 2);
|
jbe@141
|
540 json_regfetch(L, json_nullmark); // on stack position 3
|
jbe@139
|
541 json_regfetch(L, json_shadowtbl);
|
jbe@130
|
542 lua_pushvalue(L, 1);
|
jbe@141
|
543 lua_rawget(L, json_index_shadowtbl_idx);
|
jbe@139
|
544 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@130
|
545 lua_pushvalue(L, 2);
|
jbe@130
|
546 lua_rawget(L, -2);
|
jbe@141
|
547 if (lua_rawequal(L, -1, json_index_nullmark_idx)) lua_pushnil(L);
|
jbe@127
|
548 return 1;
|
jbe@127
|
549 }
|
jbe@127
|
550
|
jbe@130
|
551 static int json_newindex(lua_State *L) {
|
jbe@130
|
552 lua_settop(L, 3);
|
jbe@139
|
553 json_regfetch(L, json_shadowtbl);
|
jbe@123
|
554 lua_pushvalue(L, 1);
|
jbe@139
|
555 lua_rawget(L, -1);
|
jbe@130
|
556 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@130
|
557 lua_replace(L, 1);
|
jbe@139
|
558 lua_settop(L, 3);
|
jbe@130
|
559 lua_rawset(L, 1);
|
jbe@121
|
560 return 1;
|
jbe@121
|
561 }
|
jbe@121
|
562
|
jbe@139
|
563 #define json_pairs_iterfunc_nullmark_idx 3
|
jbe@139
|
564 #define json_pairs_iterfunc_shadowtbl_idx 4
|
jbe@139
|
565
|
jbe@135
|
566 static int json_pairs_iterfunc(lua_State *L) {
|
jbe@135
|
567 lua_settop(L, 2);
|
jbe@139
|
568 json_regfetch(L, json_nullmark); // on stack position 3
|
jbe@139
|
569 json_regfetch(L, json_shadowtbl);
|
jbe@135
|
570 lua_pushvalue(L, 1);
|
jbe@139
|
571 lua_rawget(L, json_pairs_iterfunc_shadowtbl_idx);
|
jbe@135
|
572 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@135
|
573 lua_pushvalue(L, 2);
|
jbe@135
|
574 if (!lua_next(L, -2)) return 0;
|
jbe@139
|
575 if (lua_rawequal(L, -1, json_pairs_iterfunc_nullmark_idx)) {
|
jbe@135
|
576 lua_pop(L, 1);
|
jbe@135
|
577 lua_pushnil(L);
|
jbe@135
|
578 }
|
jbe@135
|
579 return 2;
|
jbe@135
|
580 }
|
jbe@135
|
581
|
jbe@135
|
582 static int json_pairs(lua_State *L) {
|
jbe@139
|
583 lua_pushcfunction(L, json_pairs_iterfunc);
|
jbe@135
|
584 lua_pushvalue(L, 1);
|
jbe@135
|
585 lua_pushnil(L);
|
jbe@135
|
586 return 3;
|
jbe@135
|
587 }
|
jbe@135
|
588
|
jbe@139
|
589 #define json_ipairs_iterfunc_nullmark_idx 3
|
jbe@139
|
590 #define json_ipairs_iterfunc_shadowtbl_idx 4
|
jbe@139
|
591
|
jbe@134
|
592 static int json_ipairs_iterfunc(lua_State *L) {
|
jbe@134
|
593 int idx;
|
jbe@134
|
594 lua_settop(L, 2);
|
jbe@139
|
595 json_regfetch(L, json_nullmark); // on stack position 3
|
jbe@139
|
596 json_regfetch(L, json_shadowtbl);
|
jbe@134
|
597 idx = lua_tointeger(L, 2) + 1;
|
jbe@134
|
598 lua_pushvalue(L, 1);
|
jbe@139
|
599 lua_rawget(L, json_ipairs_iterfunc_shadowtbl_idx);
|
jbe@134
|
600 if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
|
jbe@134
|
601 lua_rawgeti(L, -1, idx);
|
jbe@134
|
602 if (lua_isnil(L, -1)) return 0;
|
jbe@134
|
603 lua_pushinteger(L, idx);
|
jbe@139
|
604 if (lua_rawequal(L, -2, json_ipairs_iterfunc_nullmark_idx)) lua_pushnil(L);
|
jbe@134
|
605 else lua_pushvalue(L, -2);
|
jbe@134
|
606 return 2;
|
jbe@134
|
607 }
|
jbe@134
|
608
|
jbe@134
|
609 static int json_ipairs(lua_State *L) {
|
jbe@139
|
610 lua_pushcfunction(L, json_ipairs_iterfunc);
|
jbe@134
|
611 lua_pushvalue(L, 1);
|
jbe@134
|
612 lua_pushinteger(L, 0);
|
jbe@134
|
613 return 3;
|
jbe@134
|
614 }
|
jbe@134
|
615
|
jbe@121
|
616 static const struct luaL_Reg json_module_functions[] = {
|
jbe@133
|
617 {"object", json_object},
|
jbe@133
|
618 {"array", json_array},
|
jbe@121
|
619 {"import", json_import},
|
jbe@130
|
620 {"get", json_get},
|
jbe@127
|
621 {"type", json_type},
|
jbe@123
|
622 {"isnull", json_isnull},
|
jbe@131
|
623 {"setnull", json_setnull},
|
jbe@121
|
624 {NULL, NULL}
|
jbe@121
|
625 };
|
jbe@121
|
626
|
jbe@126
|
627 static const struct luaL_Reg json_metatable_functions[] = {
|
jbe@130
|
628 {"__len", json_len},
|
jbe@130
|
629 {"__index", json_index},
|
jbe@130
|
630 {"__newindex", json_newindex},
|
jbe@135
|
631 {"__pairs", json_pairs},
|
jbe@134
|
632 {"__ipairs", json_ipairs},
|
jbe@126
|
633 {NULL, NULL}
|
jbe@126
|
634 };
|
jbe@126
|
635
|
jbe@121
|
636 int luaopen_json(lua_State *L) {
|
jbe@126
|
637 lua_settop(L, 0);
|
jbe@138
|
638 lua_newtable(L); // library
|
jbe@138
|
639 lua_newtable(L);
|
jbe@138
|
640 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@138
|
641 json_regstore(L, json_unknownmt);
|
jbe@138
|
642 lua_setfield(L, 1, "ambiguous_mt");
|
jbe@138
|
643 lua_newtable(L);
|
jbe@138
|
644 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@138
|
645 json_regstore(L, json_objectmt);
|
jbe@138
|
646 lua_setfield(L, 1, "object_mt");
|
jbe@138
|
647 lua_newtable(L);
|
jbe@138
|
648 luaL_setfuncs(L, json_metatable_functions, 0);
|
jbe@138
|
649 json_regstore(L, json_arraymt);
|
jbe@138
|
650 lua_setfield(L, 1, "array_mt");
|
jbe@138
|
651 lua_newtable(L); // ephemeron table to store shadow tables for each JSON object/array to allow NULL values returned as nil
|
jbe@138
|
652 lua_newtable(L); // metatable for ephemeron table
|
jbe@121
|
653 lua_pushliteral(L, "__mode");
|
jbe@121
|
654 lua_pushliteral(L, "k");
|
jbe@138
|
655 lua_rawset(L, -3);
|
jbe@138
|
656 lua_setmetatable(L, -2);
|
jbe@138
|
657 json_regstore(L, json_shadowtbl);
|
jbe@138
|
658 lua_newtable(L);
|
jbe@138
|
659 json_regstore(L, json_nullmark);
|
jbe@138
|
660 lua_settop(L, 1);
|
jbe@138
|
661 luaL_setfuncs(L, json_module_functions, 0);
|
jbe@121
|
662 return 1;
|
jbe@121
|
663 }
|