From 9f3d6b59c5f097d66e94f987c7731d7a4113057f Mon Sep 17 00:00:00 2001 From: Mark Pulford Date: Fri, 15 Apr 2011 23:37:41 +0930 Subject: Merge lua_json_encode/decode.c into lua_json.c --- lua_json.c | 668 ++++++++++++++++++++++++++++++++++++++++++++++++++++++ lua_json_decode.c | 405 --------------------------------- lua_json_encode.c | 256 --------------------- 3 files changed, 668 insertions(+), 661 deletions(-) create mode 100644 lua_json.c delete mode 100644 lua_json_decode.c delete mode 100644 lua_json_encode.c diff --git a/lua_json.c b/lua_json.c new file mode 100644 index 0000000..ab72dd5 --- /dev/null +++ b/lua_json.c @@ -0,0 +1,668 @@ +/* Lua JSON routines + */ + +/* Caveats: + * - No unicode support + * - JSON "null" values are represented as lightuserdata. Compare with + * json.null. + * - Parsing comments is not support. According to json.org, this isn't + * part of the spec. + */ + +/* FIXME: + * - Ensure JSON data is UTF-8. Fail otherwise. + * - Alternatively, dynamically support Unicode in JSON string. Return current locale. + * - Use lua_checkstack() to ensure there is enough stack space left to + * fulfill an operation. What happens if we don't, is that acceptible too? + * Does lua_checkstack grow the stack, or merely check if it is possible? + */ + +/* FIXME: + * - Option to encode non-printable characters? Only \" \\ are required + * - Unicode? + */ + +/* FIXME: + * - Review memory allocation handling and error returns. + * Ensure all memory is free. Including after exceptions. + */ + +#include +#include +#include + +#include +#include + +#include "lua_json.h" +#include "utils.h" +#include "strbuf.h" + +/* ===== ENCODING ===== */ + + +/* JSON escape a character if required, or return NULL */ +static inline char *json_escape_char(int c) +{ + switch(c) { + case 0: + return "\\u0000"; + case '\\': + return "\\\\"; + case '"': + return "\\\""; + case '\b': + return "\\b"; + case '\t': + return "\\t"; + case '\n': + return "\\n"; + case '\f': + return "\\f"; + case '\r': + return "\\r"; + } + + return NULL; +} + +/* json_append_string args: + * - lua_State + * - JSON strbuf + * - String (Lua stack index) + * + * Returns nothing. Doesn't remove string from Lua stack */ +static void json_append_string(lua_State *l, strbuf_t *json, int lindex) +{ + char *p; + int i; + const char *str; + size_t len; + + str = lua_tolstring(l, lindex, &len); + + strbuf_append_char(json, '\"'); + for (i = 0; i < len; i++) { + p = json_escape_char(str[i]); + if (p) + strbuf_append_string(json, p); + else + strbuf_append_char(json, str[i]); + } + strbuf_append_char(json, '\"'); +} + +/* Find the size of the array on the top of the Lua stack + * -1 object (not a pure array) + * >=0 elements in array + */ +static int lua_array_length(lua_State *l) +{ + double k; + int max; + + max = 0; + + lua_pushnil(l); + /* table, startkey */ + while (lua_next(l, -2) != 0) { + /* table, key, value */ + if ((k = lua_tonumber(l, -2))) { + /* Integer >= 1 ? */ + if (floor(k) == k && k >= 1) { + if (k > max) + max = k; + lua_pop(l, 1); + continue; + } + } + + /* Must not be an array (non integer key) */ + lua_pop(l, 2); + return -1; + } + + return max; +} + +static void json_append_data(lua_State *l, strbuf_t *json); + +/* json_append_array args: + * - lua_State + * - JSON strbuf + * - Size of passwd Lua array (top of stack) */ +static void json_append_array(lua_State *l, strbuf_t *json, int array_length) +{ + int comma, i; + + strbuf_append_string(json, "[ "); + + comma = 0; + for (i = 1; i <= array_length; i++) { + if (comma) + strbuf_append_string(json, ", "); + else + comma = 1; + + lua_rawgeti(l, -1, i); + json_append_data(l, json); + lua_pop(l, 1); + } + + strbuf_append_string(json, " ]"); +} + +static void json_append_object(lua_State *l, strbuf_t *json) +{ + int comma, keytype; + + /* Object */ + strbuf_append_string(json, "{ "); + + lua_pushnil(l); + /* table, startkey */ + comma = 0; + while (lua_next(l, -2) != 0) { + if (comma) + strbuf_append_string(json, ", "); + else + comma = 1; + + /* table, key, value */ + keytype = lua_type(l, -2); + if (keytype == LUA_TNUMBER) { + strbuf_append_fmt(json, "\"" LUA_NUMBER_FMT "\": ", + lua_tonumber(l, -2)); + } else if (keytype == LUA_TSTRING) { + json_append_string(l, json, -2); + strbuf_append_string(json, ": "); + } else { + die("Cannot serialise table key %s", lua_typename(l, lua_type(l, -2))); + } + + /* table, key, value */ + json_append_data(l, json); + lua_pop(l, 1); + /* table, key */ + } + + strbuf_append_string(json, " }"); +} + +/* Serialise Lua data into JSON string. + * + * FIXME: + * - Error handling when cannot serialise key or value (return to script) + */ +static void json_append_data(lua_State *l, strbuf_t *json) +{ + int len; + + switch (lua_type(l, -1)) { + case LUA_TSTRING: + json_append_string(l, json, -1); + break; + case LUA_TNUMBER: + strbuf_append_fmt(json, "%lf", lua_tonumber(l, -1)); + break; + case LUA_TBOOLEAN: + if (lua_toboolean(l, -1)) + strbuf_append_string(json, "true"); + else + strbuf_append_string(json, "false"); + break; + case LUA_TTABLE: + len = lua_array_length(l); + if (len >= 0) + json_append_array(l, json, len); + else + json_append_object(l, json); + break; + case LUA_TNIL: + strbuf_append_string(json, "null"); + break; + case LUA_TLIGHTUSERDATA: + if (lua_touserdata(l, -1) == NULL) { + strbuf_append_string(json, "null"); + break; + } + default: + /* Remaining types (LUA_TFUNCTION, LUA_TUSERDATA, LUA_TTHREAD, and LUA_TLIGHTUSERDATA) + * cannot be serialised */ + /* FIXME: return error */ + die("Cannot serialise %s", lua_typename(l, lua_type(l, -1))); + } +} + +char *lua_json_encode(lua_State *l, int *len) +{ + strbuf_t buf; + char *json; + + strbuf_init(&buf); + strbuf_set_increment(&buf, 256); + json_append_data(l, &buf); + json = strbuf_free_to_string(&buf, len); + + return json; +} + +int lua_api_json_encode(lua_State *l) +{ + char *json; + int len; + + json = lua_json_encode(l, &len); + lua_pushlstring(l, json, len); + free(json); + + return 1; +} + +/* ===== DECODING ===== */ + +typedef struct { + const char *data; + int index; + strbuf_t *tmp; /* Temporary storage for strings */ +} json_parse_t; + +typedef enum { + T_OBJ_BEGIN, + T_OBJ_END, + T_ARR_BEGIN, + T_ARR_END, + T_STRING, + T_NUMBER, + T_BOOLEAN, + T_NULL, + T_COLON, + T_COMMA, + T_END, + T_WHITESPACE, + T_ERROR, + T_UNKNOWN +} json_token_type_t; + +static const char *json_token_type_name[] = { + "T_OBJ_BEGIN", + "T_OBJ_END", + "T_ARR_BEGIN", + "T_ARR_END", + "T_STRING", + "T_NUMBER", + "T_BOOLEAN", + "T_NULL", + "T_COLON", + "T_COMMA", + "T_END", + "T_WHITESPACE", + "T_ERROR", + "T_UNKNOWN", + NULL +}; + +typedef struct { + json_token_type_t type; + int index; + union { + char *string; + double number; + int boolean; + } value; + int length; /* FIXME: Merge into union? Won't save memory, but more logical */ +} json_token_t; + +static void json_process_value(lua_State *l, json_parse_t *json, json_token_t *token); + +static json_token_type_t json_ch2token[256]; +static char json_ch2escape[256]; + +static void json_init_lookup_tables() +{ + int i; + + /* Tag all characters as an error */ + for (i = 0; i < 256; i++) + json_ch2token[i] = T_ERROR; + + /* Set tokens that require no further processing */ + json_ch2token['{'] = T_OBJ_BEGIN; + json_ch2token['}'] = T_OBJ_END; + json_ch2token['['] = T_ARR_BEGIN; + json_ch2token[']'] = T_ARR_END; + json_ch2token[','] = T_COMMA; + json_ch2token[':'] = T_COLON; + json_ch2token['\0'] = T_END; + json_ch2token[' '] = T_WHITESPACE; + json_ch2token['\t'] = T_WHITESPACE; + json_ch2token['\n'] = T_WHITESPACE; + json_ch2token['\r'] = T_WHITESPACE; + + /* Update characters that require further processing */ + json_ch2token['n'] = T_UNKNOWN; + json_ch2token['t'] = T_UNKNOWN; + json_ch2token['f'] = T_UNKNOWN; + json_ch2token['"'] = T_UNKNOWN; + json_ch2token['-'] = T_UNKNOWN; + for (i = 0; i < 10; i++) + json_ch2token['0' + i] = T_UNKNOWN; + + for (i = 0; i < 256; i++) + json_ch2escape[i] = 0; /* String error */ + + json_ch2escape['"'] = '"'; + json_ch2escape['\\'] = '\\'; + json_ch2escape['/'] = '/'; + json_ch2escape['b'] = '\b'; + json_ch2escape['t'] = '\t'; + json_ch2escape['n'] = '\n'; + json_ch2escape['f'] = '\f'; + json_ch2escape['r'] = '\r'; + json_ch2escape['u'] = 'u'; /* This needs to be parsed as unicode */ +} + +static void json_next_string_token(json_parse_t *json, json_token_t *token) +{ + char ch; + + /* Caller must ensure a string is next */ + assert(json->data[json->index] == '"'); + + /* Gobble string. FIXME, ugly */ + + json->tmp->length = 0; + while ((ch = json->data[++json->index]) != '"') { + /* Handle escapes */ + if (ch == '\\') { + /* Translate escape code */ + ch = json_ch2escape[(unsigned char)json->data[++json->index]]; + if (!ch) { + /* Invalid escape code */ + token->type = T_ERROR; + return; + } + if (ch == 'u') { + /* Process unicode */ + /* FIXME: cleanup memory handling. Implement iconv(3) + * conversion from UCS-2 -> UTF-8 + */ + if (!memcmp(&json->data[json->index], "u0000", 5)) { + /* Handle NULL */ + ch = 0; + json->index += 4; + } else { + /* Remaining codepoints unhandled */ + token->type = T_ERROR; + return; + } + } + } + strbuf_append_char(json->tmp, ch); + } + json->index++; /* Eat final quote (") */ + + strbuf_ensure_null(json->tmp); + + token->type = T_STRING; + token->value.string = strbuf_string(json->tmp, NULL); + token->length = json->tmp->length; +} + +static void json_next_number_token(json_parse_t *json, json_token_t *token) +{ + const char *startptr; + char *endptr; + + /* FIXME: + * Verify that the number takes the following form: + * -?(0|[1-9]|[1-9][0-9]+)(.[0-9]+)?([eE][-+]?[0-9]+)? + * strtod() below allows other forms (Hex, infinity, NaN,..) */ + /* i = json->index; + if (json->data[i] == '-') + i++; + j = i; + while ('0' <= json->data[i] && json->data[i] <= '9') + i++; + if (i == j) + return T_ERROR; */ + + token->type = T_NUMBER; + startptr = &json->data[json->index]; + token->value.number = strtod(&json->data[json->index], &endptr); + if (startptr == endptr) + token->type = T_ERROR; + else + json->index += endptr - startptr; /* Skip the processed number */ + + return; +} + +/* Fills in the token struct. + * T_STRING will return a pointer to the json_parse_t temporary string + * T_ERROR will leave the json->index pointer at the error. + */ +static void json_next_token(json_parse_t *json, json_token_t *token) +{ + int ch; + + /* Eat whitespace. FIXME: UGLY */ + token->type = json_ch2token[(unsigned char)json->data[json->index]]; + while (token->type == T_WHITESPACE) + token->type = json_ch2token[(unsigned char)json->data[++json->index]]; + + token->index = json->index; + + /* Don't advance the pointer for an error or the end */ + if (token->type == T_ERROR || token->type == T_END) + return; + + /* Found a known token, advance index and return */ + if (token->type != T_UNKNOWN) { + json->index++; + return; + } + + /* Process characters which triggered T_UNKNOWN */ + ch = json->data[json->index]; + + if (ch == '"') { + json_next_string_token(json, token); + return; + } else if (ch == '-' || ('0' <= ch && ch <= '9')) { + json_next_number_token(json, token); + return; + } else if (!strncmp(&json->data[json->index], "true", 4)) { + token->type = T_BOOLEAN; + token->value.boolean = 1; + json->index += 4; + return; + } else if (!strncmp(&json->data[json->index], "false", 5)) { + token->type = T_BOOLEAN; + token->value.boolean = 0; + json->index += 5; + return; + } else if (!strncmp(&json->data[json->index], "null", 4)) { + token->type = T_NULL; + json->index += 4; + return; + } + + token->type = T_ERROR; +} + +/* This function does not return. + * DO NOT CALL WITH DYNAMIC MEMORY ALLOCATED. + * The only allowed exception is the temporary parser string + * json->tmp struct. + * json and token should exist on the stack somewhere. + * luaL_error() will long_jmp and release the stack */ +static void json_throw_parse_error(lua_State *l, json_parse_t *json, + const char *exp, json_token_t *token) +{ + strbuf_free(json->tmp); + luaL_error(l, "Expected %s but found type <%s> at character %d", + exp, json_token_type_name[token->type], token->index); +} + +static void json_parse_object_context(lua_State *l, json_parse_t *json) +{ + json_token_t token; + + lua_newtable(l); + + json_next_token(json, &token); + + /* Handle empty objects */ + if (token.type == T_OBJ_END) + return; + + while (1) { + if (token.type != T_STRING) + json_throw_parse_error(l, json, "object key", &token); + + lua_pushlstring(l, token.value.string, token.length); /* Push key */ + + json_next_token(json, &token); + if (token.type != T_COLON) + json_throw_parse_error(l, json, "colon", &token); + + json_next_token(json, &token); + json_process_value(l, json, &token); + lua_rawset(l, -3); /* Set key = value */ + + json_next_token(json, &token); + + if (token.type == T_OBJ_END) + return; + + if (token.type != T_COMMA) + json_throw_parse_error(l, json, "comma or object end", &token); + + json_next_token(json, &token); + } +} + +/* Handle the array context */ +static void json_parse_array_context(lua_State *l, json_parse_t *json) +{ + json_token_t token; + int i; + + lua_newtable(l); + + json_next_token(json, &token); + + /* Handle empty arrays */ + if (token.type == T_ARR_END) + return; + + i = 1; + while (1) { + json_process_value(l, json, &token); + lua_rawseti(l, -2, i); /* arr[i] = value */ + + json_next_token(json, &token); + + if (token.type == T_ARR_END) + return; + + if (token.type != T_COMMA) + json_throw_parse_error(l, json, "comma or array end", &token); + + json_next_token(json, &token); + i++; + } +} + +/* Handle the "value" context */ +static void json_process_value(lua_State *l, json_parse_t *json, json_token_t *token) +{ + switch (token->type) { + case T_STRING: + lua_pushlstring(l, token->value.string, token->length); + break;; + case T_NUMBER: + lua_pushnumber(l, token->value.number); + break;; + case T_BOOLEAN: + lua_pushboolean(l, token->value.boolean); + break;; + case T_OBJ_BEGIN: + json_parse_object_context(l, json); + break;; + case T_ARR_BEGIN: + json_parse_array_context(l, json); + break;; + case T_NULL: + /* In Lua, setting "t[k] = nil" will delete k from the table. + * Hence a NULL pointer lightuserdata object is used instead */ + lua_pushlightuserdata(l, NULL); + break;; + default: + json_throw_parse_error(l, json, "value", token); + } +} + +/* json_text must be null terminated string */ +void lua_json_decode(lua_State *l, const char *json_text) +{ + json_parse_t json; + json_token_t token; + + json.data = json_text; + json.index = 0; + json.tmp = strbuf_new(); + strbuf_set_increment(json.tmp, 256); + + json_next_token(&json, &token); + json_process_value(l, &json, &token); + + /* Ensure there is no more input left */ + json_next_token(&json, &token); + + if (token.type != T_END) + json_throw_parse_error(l, &json, "the end", &token); + + strbuf_free(json.tmp); +} + +static int lua_api_json_decode(lua_State *l) +{ + int i, n; + + n = lua_gettop(l); + + for (i = 1; i <= n; i++) { + if (lua_isstring(l, i)) { + lua_json_decode(l, lua_tostring(l, i)); + } else { + lua_pushnil(l); + } + } + + return n; /* Number of results */ +} + +/* ===== INITIALISATION ===== */ + +void lua_json_init(lua_State *l) +{ + luaL_Reg reg[] = { + { "encode", lua_api_json_encode }, + { "decode", lua_api_json_decode }, + { NULL, NULL } + }; + + json_init_lookup_tables(); + + luaL_register(l, "json", reg); + + /* Set json.null, and pop "json" table from the stack */ + lua_pushlightuserdata(l, NULL); + lua_setfield(l, -2, "null"); + lua_pop(l, 1); +} + +/* vi:ai et sw=4 ts=4: + */ diff --git a/lua_json_decode.c b/lua_json_decode.c deleted file mode 100644 index ae35574..0000000 --- a/lua_json_decode.c +++ /dev/null @@ -1,405 +0,0 @@ -#include -#include -#include -#include -#include "strbuf.h" - -/* Caveats: - * - NULL values do not work in objects (unssuported by Lua tables). - * - Could use a secial "null" table object, that is unique - * - NULL values work in arrays (probably not at the end) - */ - -/* FIXME: - * - Ensure JSON data is UTF-8. Fail otherwise. - * - Alternatively, dynamically support Unicode in JSON string. Return current locale. - * - Use lua_checkstack() to ensure there is enough stack space left to - * fulfill an operation. What happens if we don't, is that acceptible too? - * Does lua_checkstack grow the stack, or merely check if it is possible? - * - Merge encode/decode files - */ - -typedef struct { - const char *data; - int index; - strbuf_t *tmp; /* Temporary storage for strings */ -} json_parse_t; - -typedef enum { - T_OBJ_BEGIN, - T_OBJ_END, - T_ARR_BEGIN, - T_ARR_END, - T_STRING, - T_NUMBER, - T_BOOLEAN, - T_NULL, - T_COLON, - T_COMMA, - T_END, - T_WHITESPACE, - T_ERROR, - T_UNKNOWN -} json_token_type_t; - -static const char *json_token_type_name[] = { - "T_OBJ_BEGIN", - "T_OBJ_END", - "T_ARR_BEGIN", - "T_ARR_END", - "T_STRING", - "T_NUMBER", - "T_BOOLEAN", - "T_NULL", - "T_COLON", - "T_COMMA", - "T_END", - "T_WHITESPACE", - "T_ERROR", - "T_UNKNOWN", - NULL -}; - -typedef struct { - json_token_type_t type; - int index; - union { - char *string; - double number; - int boolean; - } value; - int length; /* FIXME: Merge into union? Won't save memory, but more logical */ -} json_token_t; - -static void json_process_value(lua_State *l, json_parse_t *json, json_token_t *token); - -static json_token_type_t json_ch2token[256]; -static char json_ch2escape[256]; - -void json_init_lookup_tables() -{ - int i; - - /* Tag all characters as an error */ - for (i = 0; i < 256; i++) - json_ch2token[i] = T_ERROR; - - /* Set tokens that require no further processing */ - json_ch2token['{'] = T_OBJ_BEGIN; - json_ch2token['}'] = T_OBJ_END; - json_ch2token['['] = T_ARR_BEGIN; - json_ch2token[']'] = T_ARR_END; - json_ch2token[','] = T_COMMA; - json_ch2token[':'] = T_COLON; - json_ch2token['\0'] = T_END; - json_ch2token[' '] = T_WHITESPACE; - json_ch2token['\t'] = T_WHITESPACE; - json_ch2token['\n'] = T_WHITESPACE; - json_ch2token['\r'] = T_WHITESPACE; - - /* Update characters that require further processing */ - json_ch2token['n'] = T_UNKNOWN; - json_ch2token['t'] = T_UNKNOWN; - json_ch2token['f'] = T_UNKNOWN; - json_ch2token['"'] = T_UNKNOWN; - json_ch2token['-'] = T_UNKNOWN; - for (i = 0; i < 10; i++) - json_ch2token['0' + i] = T_UNKNOWN; - - for (i = 0; i < 256; i++) - json_ch2escape[i] = 0; /* String error */ - - json_ch2escape['"'] = '"'; - json_ch2escape['\\'] = '\\'; - json_ch2escape['/'] = '/'; - json_ch2escape['b'] = '\b'; - json_ch2escape['t'] = '\t'; - json_ch2escape['n'] = '\n'; - json_ch2escape['f'] = '\f'; - json_ch2escape['r'] = '\r'; - json_ch2escape['u'] = 'u'; /* This needs to be parsed as unicode */ -} - -static void json_next_string_token(json_parse_t *json, json_token_t *token) -{ - char ch; - - /* Caller must ensure a string is next */ - assert(json->data[json->index] == '"'); - - /* Gobble string. FIXME, ugly */ - - json->tmp->length = 0; - while ((ch = json->data[++json->index]) != '"') { - /* Handle escapes */ - if (ch == '\\') { - /* Translate escape code */ - ch = json_ch2escape[(unsigned char)json->data[++json->index]]; - if (!ch) { - /* Invalid escape code */ - token->type = T_ERROR; - return; - } - if (ch == 'u') { - /* Process unicode */ - /* FIXME: cleanup memory handling. Implement iconv(3) - * conversion from UCS-2 -> UTF-8 - */ - if (!memcmp(&json->data[json->index], "u0000", 5)) { - /* Handle NULL */ - ch = 0; - json->index += 4; - } else { - /* Remaining codepoints unhandled */ - token->type = T_ERROR; - return; - } - } - } - strbuf_append_char(json->tmp, ch); - } - json->index++; /* Eat final quote (") */ - - strbuf_ensure_null(json->tmp); - - token->type = T_STRING; - token->value.string = json->tmp->data; - token->length = json->tmp->length; -} - -static void json_next_number_token(json_parse_t *json, json_token_t *token) -{ - const char *startptr; - char *endptr; - - /* FIXME: - * Verify that the number takes the following form: - * -?(0|[1-9]|[1-9][0-9]+)(.[0-9]+)?([eE][-+]?[0-9]+)? - * strtod() below allows other forms (Hex, infinity, NaN,..) */ - /* i = json->index; - if (json->data[i] == '-') - i++; - j = i; - while ('0' <= json->data[i] && json->data[i] <= '9') - i++; - if (i == j) - return T_ERROR; */ - - token->type = T_NUMBER; - startptr = &json->data[json->index]; - token->value.number = strtod(&json->data[json->index], &endptr); - if (startptr == endptr) - token->type = T_ERROR; - else - json->index += endptr - startptr; /* Skip the processed number */ - - return; -} - -/* Fills in the token struct. - * T_STRING will return a pointer to the json_parse_t temporary string - * T_ERROR will leave the json->index pointer at the error. - */ -static void json_next_token(json_parse_t *json, json_token_t *token) -{ - int ch; - - /* Eat whitespace. FIXME: UGLY */ - token->type = json_ch2token[(unsigned char)json->data[json->index]]; - while (token->type == T_WHITESPACE) - token->type = json_ch2token[(unsigned char)json->data[++json->index]]; - - token->index = json->index; - - /* Don't advance the pointer for an error or the end */ - if (token->type == T_ERROR || token->type == T_END) - return; - - /* Found a known token, advance index and return */ - if (token->type != T_UNKNOWN) { - json->index++; - return; - } - - ch = json->data[json->index]; - - /* Process characters which triggered T_UNKNOWN */ - if (ch == '"') { - json_next_string_token(json, token); - return; - } else if (ch == '-' || ('0' <= ch && ch <= '9')) { - json_next_number_token(json, token); - return; - } else if (!strncmp(&json->data[json->index], "true", 4)) { - token->type = T_BOOLEAN; - token->value.boolean = 1; - json->index += 4; - return; - } else if (!strncmp(&json->data[json->index], "false", 5)) { - token->type = T_BOOLEAN; - token->value.boolean = 0; - json->index += 5; - return; - } else if (!strncmp(&json->data[json->index], "null", 4)) { - token->type = T_NULL; - json->index += 4; - return; - } - - token->type = T_ERROR; -} - -/* This function does not return. - * DO NOT CALL WITH DYNAMIC MEMORY ALLOCATED. - * The only allowed exception is the temporary parser string - * json->tmp struct. - * json and token should exist on the stack somewhere. - * luaL_error() will long_jmp and release the stack */ -static void json_throw_parse_error(lua_State *l, json_parse_t *json, - const char *exp, json_token_t *token) -{ - strbuf_free(json->tmp); - luaL_error(l, "Expected %s but found type <%s> at character %d", - exp, json_token_type_name[token->type], token->index); -} - -static void json_parse_object_context(lua_State *l, json_parse_t *json) -{ - json_token_t token; - - lua_newtable(l); - - json_next_token(json, &token); - - /* Handle empty objects */ - if (token.type == T_OBJ_END) - return; - - while (1) { - if (token.type != T_STRING) - json_throw_parse_error(l, json, "object key", &token); - - lua_pushlstring(l, token.value.string, token.length); /* Push key */ - - json_next_token(json, &token); - if (token.type != T_COLON) - json_throw_parse_error(l, json, "colon", &token); - - json_next_token(json, &token); - json_process_value(l, json, &token); - lua_rawset(l, -3); /* Set key = value */ - - json_next_token(json, &token); - - if (token.type == T_OBJ_END) - return; - - if (token.type != T_COMMA) - json_throw_parse_error(l, json, "comma or object end", &token); - - json_next_token(json, &token); - } while (1); - -} - -/* Handle the array context */ -static void json_parse_array_context(lua_State *l, json_parse_t *json) -{ - json_token_t token; - int i; - - lua_newtable(l); - - json_next_token(json, &token); - - /* Handle empty arrays */ - if (token.type == T_ARR_END) - return; - - i = 1; - while (1) { - json_process_value(l, json, &token); - lua_rawseti(l, -2, i); /* arr[i] = value */ - - json_next_token(json, &token); - - if (token.type == T_ARR_END) - return; - - if (token.type != T_COMMA) - json_throw_parse_error(l, json, "comma or array end", &token); - - json_next_token(json, &token); - i++; - } -} - -/* Handle the "value" context */ -static void json_process_value(lua_State *l, json_parse_t *json, json_token_t *token) -{ - switch (token->type) { - case T_STRING: - lua_pushlstring(l, token->value.string, token->length); - break;; - case T_NUMBER: - lua_pushnumber(l, token->value.number); - break;; - case T_BOOLEAN: - lua_pushboolean(l, token->value.boolean); - break;; - case T_OBJ_BEGIN: - json_parse_object_context(l, json); - break;; - case T_ARR_BEGIN: - json_parse_array_context(l, json); - break;; - case T_NULL: - lua_pushnil(l); - break;; - default: - json_throw_parse_error(l, json, "value", token); - } -} - -/* json_text must be null terminated string */ -void json_parse(lua_State *l, const char *json_text) -{ - json_parse_t json; - json_token_t token; - - json.data = json_text; - json.index = 0; - json.tmp = strbuf_new(); - json.tmp->scale = 256; - - json_next_token(&json, &token); - json_process_value(l, &json, &token); - - /* Ensure there is no more input left */ - json_next_token(&json, &token); - - if (token.type != T_END) - json_throw_parse_error(l, &json, "the end", &token); - - strbuf_free(json.tmp); -} - -int lua_json_decode(lua_State *l) -{ - int i, n; - - n = lua_gettop(l); - - for (i = 1; i <= n; i++) { - if (lua_isstring(l, i)) { - json_parse(l, lua_tostring(l, i)); - } else { - lua_pushnil(l); - } - } - - return n; /* Number of results */ -} - -/* vi:ai et sw=4 ts=4: - */ diff --git a/lua_json_encode.c b/lua_json_encode.c deleted file mode 100644 index 201f769..0000000 --- a/lua_json_encode.c +++ /dev/null @@ -1,256 +0,0 @@ -/* - * Lua JSON routines - * - * CAVEATS: - * - JSON "null" handling: - * - Decoding a "null" in an array will leave a "nil" placeholder in Lua, but will not show up at the end of the array. - * - Decoding a "null" in an object will ensure that particular key is deleted in the Lua table. - */ - -#include -#include - -#include -#include -#include - -#include "lua_json.h" -#include "utils.h" -#include "str.h" - -/* FIXME: - * - Don't just pushnil on error and return? - * - Review all strbuf usage for NULL termination - */ - -/* JSON escape a character if required, or return NULL */ -static inline char *json_escape_char(int c) -{ - switch(c) { - case 0: - return "\\u0000"; - case '\\': - return "\\\\"; - case '"': - return "\\\""; - case '\b': - return "\\b"; - case '\t': - return "\\t"; - case '\n': - return "\\n"; - case '\f': - return "\\f"; - case '\r': - return "\\r"; - } - - return NULL; -} - -/* FIXME: - * - Use lua_checklstring() instead of lua_tolstring() ?* - */ - -/* FIXME: - * - Option to encode non-printable characters? Only \" \\ are required - * - Unicode? - * - Improve performance? - */ -static void json_append_string(lua_State *l, struct str *json, int index) -{ - char *p; - int i; - const char *str; - size_t len; - - str = lua_tolstring(l, index, &len); - - strbuf_append_char(json, '\"'); - for (i = 0; i < len; i++) { - p = json_escape_char(str[i]); - if (p) - strbuf_append_mem(json, p, strlen(p)); - else - strbuf_append_char(json, str[i]); - } - strbuf_append_char(json, '\"'); -} - -/* Find the size of the array on the top of the Lua stack - * -1 object - * >=0 elements in array - */ -static int lua_array_length(lua_State *l) -{ - double k; - int max; - - max = 0; - - lua_pushnil(l); - /* table, startkey */ - while (lua_next(l, -2) != 0) { - /* table, key, value */ - if ((k = lua_tonumber(l, -2))) { - /* Integer >= 1 ? */ - if (floor(k) == k && k >= 1) { - if (k > max) - max = k; - lua_pop(l, 1); - continue; - } - } - - /* Must not be an array (non integer key) */ - lua_pop(l, 2); - return -1; - } - - return max; -} - -static void json_append_data(lua_State *l, struct str *s); - -static void json_append_array(lua_State *l, struct str *s, int size) -{ - int comma, i; - - strbuf_append_mem(s, "[ ", 2); - - comma = 0; - for (i = 1; i <= size; i++) { - if (comma) - strbuf_append_mem(s, ", ", 2); - else - comma = 1; - - lua_rawgeti(l, -1, i); - json_append_data(l, s); - lua_pop(l, 1); - } - - strbuf_append_mem(s, " ]", 2); -} - -static void json_append_object(lua_State *l, struct str *s) -{ - int comma, keytype; - - /* Object */ - strbuf_append_mem(s, "{ ", 2); - - lua_pushnil(l); - /* table, startkey */ - comma = 0; - while (lua_next(l, -2) != 0) { - if (comma) - strbuf_append_mem(s, ", ", 2); - else - comma = 1; - - /* table, key, value */ - keytype = lua_type(l, -2); - if (keytype == LUA_TNUMBER) { - strbuf_append(s, "\"" LUA_NUMBER_FMT "\": ", lua_tonumber(l, -2)); - } else if (keytype == LUA_TSTRING) { - json_append_string(l, s, -2); - strbuf_append_mem(s, ": ", 2); - } else { - die("Cannot serialise table key %s", lua_typename(l, lua_type(l, -2))); - } - - /* table, key, value */ - json_append_data(l, s); - lua_pop(l, 1); - /* table, key */ - } - - strbuf_append_mem(s, " }", 2); -} - -/* Serialise Lua data into JSON string. - * - * FIXME: - * - Error handling when cannot serialise key or value (return to script) - */ -static void json_append_data(lua_State *l, struct str *s) -{ - int len; - - switch (lua_type(l, -1)) { - case LUA_TSTRING: - json_append_string(l, s, -1); - break; - case LUA_TNUMBER: - strbuf_append(s, "%lf", lua_tonumber(l, -1)); - break; - case LUA_TBOOLEAN: - if (lua_toboolean(l, -1)) - strbuf_append_mem(s, "true", 4); - else - strbuf_append_mem(s, "false", 5); - break; - case LUA_TTABLE: - len = lua_array_length(l); - if (len >= 0) - json_append_array(l, s, len); - else - json_append_object(l, s); - break; - case LUA_TNIL: - strbuf_append_mem(s, "null", 4); - break; - default: - /* Remaining types (LUA_TFUNCTION, LUA_TUSERDATA, LUA_TTHREAD, and LUA_TLIGHTUSERDATA) - * cannot be serialised */ - /* FIXME: return error */ - die("Cannot serialise %s", lua_typename(l, lua_type(l, -1))); - } -} - -char *lua_to_json(lua_State *l, int *len) -{ - struct str *s; - char *data; - - s = strbuf_new(); - strbuf_set_increment(s, 256); - json_append_data(l, s); - data = strbuf_to_char(s, len); - - return data; -} - -int lua_json_encode(lua_State *l) -{ - char *json; - int len; - - json = lua_to_json(l, &len); - lua_pushlstring(l, json, len); - free(json); - - return 1; -} - -void lua_json_init(lua_State *l) -{ - luaL_Reg reg[] = { - { "encode", lua_json_encode }, - { "decode", lua_json_decode }, - { NULL, NULL } - }; - - /* Create "db" table. - * Added functions as table entries - */ - - luaL_register(l, "json", reg); - - /* FIXME: Debugging */ - json_init_lookup_tables(); -} - -/* vi:ai et sw=4 ts=4: - */ -- cgit v1.2.3-55-g6feb