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annotate libraries/json/json.c @ 124:ece4e6f683c9

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Fixed namespace problems in JSON library code
author jbe
date Sat Jul 26 23:40:43 2014 +0200 (2014-07-26)
parents 402fce94f98c
children e3e5bf890aad
rev   line source
jbe@121 1 #include <lua.h>
jbe@121 2 #include <lauxlib.h>
jbe@122 3 #include <stdlib.h>
jbe@121 4 #include <string.h>
jbe@121 5
jbe@123 6 #define JSON_UPVAL_ARYLEN lua_upvalueindex(1)
jbe@123 7 #define JSON_UPVAL_NULLS lua_upvalueindex(2)
jbe@124 8 #define JSON_UPVAL_METATABLE lua_upvalueindex(3)
jbe@123 9
jbe@124 10 #define JSON_STATE_VALUE 0
jbe@124 11 #define JSON_STATE_OBJECT_KEY 1
jbe@124 12 #define JSON_STATE_OBJECT_KEY_TERMINATOR 2
jbe@124 13 #define JSON_STATE_OBJECT_VALUE 3
jbe@124 14 #define JSON_STATE_OBJECT_SEPARATOR 4
jbe@124 15 #define JSON_STATE_ARRAY_VALUE 5
jbe@124 16 #define JSON_STATE_ARRAY_SEPARATOR 6
jbe@124 17 #define JSON_STATE_END 7
jbe@121 18
jbe@121 19 static int json_import(lua_State *L) {
jbe@121 20 const char *str;
jbe@121 21 size_t total;
jbe@121 22 size_t pos = 0;
jbe@121 23 size_t level = 0;
jbe@124 24 int mode = JSON_STATE_VALUE;
jbe@121 25 char c;
jbe@121 26 luaL_Buffer luabuf;
jbe@121 27 char *cbuf;
jbe@121 28 size_t writepos;
jbe@121 29 int aryidx;
jbe@121 30 lua_settop(L, 1);
jbe@121 31 str = lua_tostring(L, 1);
jbe@121 32 total = strlen(str);
jbe@121 33 json_import_loop:
jbe@121 34 while (c = str[pos], c == ' ' || c == '\n' || c == '\r' || c == '\t' || c == '\f') pos++;
jbe@121 35 switch (c) {
jbe@121 36 case 0:
jbe@124 37 if (mode == JSON_STATE_END) return 1;
jbe@121 38 json_import_unexpected_eof:
jbe@121 39 lua_pushnil(L);
jbe@121 40 if (level == 0) lua_pushliteral(L, "Empty string");
jbe@121 41 else lua_pushliteral(L, "Unexpected end of JSON document");
jbe@121 42 return 2;
jbe@121 43 case '{':
jbe@124 44 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
jbe@121 45 goto json_import_syntax_error;
jbe@121 46 pos++;
jbe@121 47 lua_newtable(L);
jbe@123 48 lua_newtable(L); // stores set of NULL values
jbe@123 49 lua_pushvalue(L, -2);
jbe@123 50 lua_pushvalue(L, -2);
jbe@123 51 lua_rawset(L, JSON_UPVAL_NULLS);
jbe@124 52 mode = JSON_STATE_OBJECT_KEY;
jbe@121 53 level++;
jbe@121 54 goto json_import_loop;
jbe@121 55 case '[':
jbe@124 56 if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
jbe@121 57 goto json_import_syntax_error;
jbe@121 58 pos++;
jbe@121 59 lua_newtable(L);
jbe@123 60 lua_newtable(L); // stores set of NULL values
jbe@123 61 lua_pushvalue(L, -2);
jbe@123 62 lua_pushvalue(L, -2);
jbe@123 63 lua_rawset(L, JSON_UPVAL_NULLS);
jbe@121 64 lua_pushinteger(L, 0); // length of array (since it may contain nil's)
jbe@124 65 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 66 level++;
jbe@121 67 goto json_import_loop;
jbe@121 68 case '}':
jbe@124 69 if (mode != JSON_STATE_OBJECT_KEY && mode != JSON_STATE_OBJECT_SEPARATOR)
jbe@121 70 goto json_import_syntax_error;
jbe@121 71 goto json_import_close;
jbe@121 72 case ']':
jbe@124 73 if (mode != JSON_STATE_ARRAY_VALUE && mode != JSON_STATE_ARRAY_SEPARATOR)
jbe@121 74 goto json_import_syntax_error;
jbe@121 75 lua_pushvalue(L, -2); // use array table as key
jbe@121 76 lua_insert(L, -2); // use length of array as value
jbe@123 77 lua_rawset(L, JSON_UPVAL_ARYLEN); // store length in ephemeron table
jbe@121 78 // leaves array table on top of stack
jbe@121 79 json_import_close:
jbe@121 80 pos++;
jbe@123 81 lua_pop(L, 1); // pop table that stores set of NULL values
jbe@121 82 if (--level) {
jbe@121 83 if (lua_type(L, -2) == LUA_TNUMBER) {
jbe@124 84 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 85 } else {
jbe@124 86 mode = JSON_STATE_OBJECT_VALUE;
jbe@121 87 }
jbe@121 88 goto json_import_process_value;
jbe@121 89 } else {
jbe@124 90 mode = JSON_STATE_END;
jbe@121 91 }
jbe@121 92 goto json_import_loop;
jbe@121 93 case ':':
jbe@124 94 if (mode != JSON_STATE_OBJECT_KEY_TERMINATOR)
jbe@121 95 goto json_import_syntax_error;
jbe@121 96 pos++;
jbe@124 97 mode = JSON_STATE_OBJECT_VALUE;
jbe@121 98 goto json_import_loop;
jbe@121 99 case ',':
jbe@124 100 if (mode == JSON_STATE_OBJECT_SEPARATOR) {
jbe@124 101 mode = JSON_STATE_OBJECT_KEY;
jbe@124 102 } else if (mode == JSON_STATE_ARRAY_SEPARATOR) {
jbe@124 103 mode = JSON_STATE_ARRAY_VALUE;
jbe@121 104 } else {
jbe@121 105 goto json_import_syntax_error;
jbe@121 106 }
jbe@121 107 pos++;
jbe@121 108 goto json_import_loop;
jbe@121 109 case '"':
jbe@121 110 cbuf = luaL_buffinitsize(L, &luabuf, total-pos);
jbe@121 111 writepos = 0;
jbe@121 112 pos++;
jbe@121 113 while ((c = str[pos++]) != '"') {
jbe@121 114 if (c == 0) {
jbe@121 115 goto json_import_unexpected_eof;
jbe@121 116 } else if (c < 32 || c == 127) {
jbe@121 117 lua_pushnil(L);
jbe@121 118 lua_pushliteral(L, "Unexpected control character in JSON string");
jbe@121 119 return 2;
jbe@121 120 } else if (c == '\\') {
jbe@121 121 c = str[pos++];
jbe@121 122 switch (c) {
jbe@121 123 case 0:
jbe@121 124 goto json_import_unexpected_eof;
jbe@121 125 case '"':
jbe@121 126 case '/':
jbe@121 127 case '\\':
jbe@121 128 cbuf[writepos++] = c;
jbe@121 129 break;
jbe@121 130 case 'b':
jbe@121 131 cbuf[writepos++] = '\b';
jbe@121 132 break;
jbe@121 133 case 'f':
jbe@121 134 cbuf[writepos++] = '\f';
jbe@121 135 break;
jbe@121 136 case 'n':
jbe@121 137 cbuf[writepos++] = '\n';
jbe@121 138 break;
jbe@121 139 case 'r':
jbe@121 140 cbuf[writepos++] = '\r';
jbe@121 141 break;
jbe@121 142 case 't':
jbe@121 143 cbuf[writepos++] = '\t';
jbe@121 144 break;
jbe@121 145 case 'u':
jbe@121 146 lua_pushnil(L);
jbe@121 147 lua_pushliteral(L, "JSON unicode escape sequences are not implemented yet"); // TODO
jbe@121 148 return 2;
jbe@121 149 default:
jbe@121 150 lua_pushnil(L);
jbe@121 151 lua_pushliteral(L, "Unexpected string escape sequence in JSON document");
jbe@121 152 return 2;
jbe@121 153 }
jbe@121 154 } else {
jbe@121 155 cbuf[writepos++] = c;
jbe@121 156 }
jbe@121 157 }
jbe@121 158 if (!c) goto json_import_unexpected_eof;
jbe@121 159 luaL_pushresultsize(&luabuf, writepos);
jbe@121 160 goto json_import_process_value;
jbe@121 161 }
jbe@122 162 if (c == '-' || (c >= '0' && c <= '9')) {
jbe@122 163 char *endptr;
jbe@122 164 double numval;
jbe@122 165 numval = strtod(str+pos, &endptr);
jbe@122 166 if (endptr == str+pos) goto json_import_syntax_error;
jbe@122 167 pos += endptr - (str+pos);
jbe@122 168 lua_pushnumber(L, numval);
jbe@122 169 } else if (!strncmp(str+pos, "true", 4)) {
jbe@121 170 lua_pushboolean(L, 1);
jbe@121 171 pos += 4;
jbe@121 172 } else if (!strncmp(str+pos, "false", 5)) {
jbe@121 173 lua_pushboolean(L, 0);
jbe@121 174 pos += 5;
jbe@121 175 } else if (!strncmp(str+pos, "null", 4)) {
jbe@121 176 lua_pushnil(L);
jbe@121 177 pos += 4;
jbe@121 178 } else {
jbe@121 179 goto json_import_syntax_error;
jbe@121 180 }
jbe@121 181 json_import_process_value:
jbe@121 182 switch (mode) {
jbe@124 183 case JSON_STATE_OBJECT_KEY:
jbe@121 184 if (lua_type(L, -1) != LUA_TSTRING) goto json_import_syntax_error;
jbe@124 185 mode = JSON_STATE_OBJECT_KEY_TERMINATOR;
jbe@121 186 goto json_import_loop;
jbe@124 187 case JSON_STATE_OBJECT_VALUE:
jbe@123 188 if (lua_isnil(L, -1)) {
jbe@123 189 lua_pushvalue(L, -2);
jbe@123 190 lua_pushboolean(L, 1);
jbe@123 191 lua_rawset(L, -5);
jbe@123 192 }
jbe@123 193 lua_rawset(L, -4);
jbe@124 194 mode = JSON_STATE_OBJECT_SEPARATOR;
jbe@121 195 goto json_import_loop;
jbe@124 196 case JSON_STATE_ARRAY_VALUE:
jbe@121 197 aryidx = lua_tointeger(L, -2) + 1;
jbe@123 198 if (lua_isnil(L, -1)) {
jbe@123 199 lua_pushinteger(L, aryidx);
jbe@123 200 lua_pushboolean(L, 1);
jbe@123 201 lua_rawset(L, -5);
jbe@123 202 }
jbe@123 203 lua_rawseti(L, -4, aryidx);
jbe@121 204 lua_pop(L, 1);
jbe@121 205 lua_pushinteger(L, aryidx);
jbe@124 206 mode = JSON_STATE_ARRAY_SEPARATOR;
jbe@121 207 goto json_import_loop;
jbe@124 208 case JSON_STATE_VALUE:
jbe@124 209 mode = JSON_STATE_END;
jbe@121 210 goto json_import_loop;
jbe@121 211 }
jbe@121 212 json_import_syntax_error:
jbe@121 213 lua_pushnil(L);
jbe@121 214 lua_pushliteral(L, "Syntax error in JSON document");
jbe@121 215 return 2;
jbe@121 216 }
jbe@121 217
jbe@121 218 static int json_arylen(lua_State *L) {
jbe@121 219 lua_settop(L, 1);
jbe@123 220 lua_rawget(L, JSON_UPVAL_ARYLEN);
jbe@123 221 return 1;
jbe@123 222 }
jbe@123 223
jbe@123 224 static int json_isnull(lua_State *L) {
jbe@123 225 lua_pushvalue(L, 1);
jbe@123 226 lua_rawget(L, JSON_UPVAL_NULLS);
jbe@123 227 if (lua_isnil(L, -1)) goto json_isnull_false;
jbe@123 228 lua_pushvalue(L, 2);
jbe@123 229 lua_rawget(L, -2);
jbe@123 230 if (!lua_isnil(L, -1)) return 1;
jbe@123 231 json_isnull_false:
jbe@123 232 lua_pushboolean(L, 0);
jbe@121 233 return 1;
jbe@121 234 }
jbe@121 235
jbe@121 236 static const struct luaL_Reg json_module_functions[] = {
jbe@121 237 {"import", json_import},
jbe@121 238 {"arylen", json_arylen},
jbe@123 239 {"isnull", json_isnull},
jbe@121 240 {NULL, NULL}
jbe@121 241 };
jbe@121 242
jbe@121 243 int luaopen_json(lua_State *L) {
jbe@121 244 lua_newtable(L); // library table
jbe@121 245 lua_newtable(L); // ephemeron table to store the length of arrays (that may contain nil's)
jbe@123 246 lua_newtable(L); // ephemeron table to store a set of keys associated with JSON-null values
jbe@121 247 lua_newtable(L); // meta table for ephemeron table
jbe@121 248 lua_pushliteral(L, "__mode");
jbe@121 249 lua_pushliteral(L, "k");
jbe@121 250 lua_rawset(L, -3);
jbe@123 251 lua_pushvalue(L, -1);
jbe@123 252 lua_setmetatable(L, -3);
jbe@121 253 lua_setmetatable(L, -2);
jbe@123 254 luaL_setfuncs(L, json_module_functions, 2);
jbe@121 255 return 1;
jbe@121 256 }

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