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-rw-r--r-- | sca-cpp/trunk/unmaintained/modules/json/json.hpp | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/sca-cpp/trunk/unmaintained/modules/json/json.hpp b/sca-cpp/trunk/unmaintained/modules/json/json.hpp new file mode 100644 index 0000000000..85579c1b28 --- /dev/null +++ b/sca-cpp/trunk/unmaintained/modules/json/json.hpp @@ -0,0 +1,197 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +/* $Rev$ $Date$ */ + +#ifndef tuscany_json_hpp +#define tuscany_json_hpp + +/** + * JSON data conversion functions. + */ + +#include "string.hpp" +#include "list.hpp" +#include "value.hpp" +#include "element.hpp" +#include "monad.hpp" +#include "../js/eval.hpp" + +namespace tuscany { +namespace json { + +/** + * Return true if a list of strings contains a JSON document. + */ +const bool isJSON(const list<string>& ls) { + if (isNil(ls)) + return false; + const string s = substr(car(ls), 0, 1); + return s == "[" || s == "{"; +} + +/** + * Consumes JSON strings and populates a JS object. + */ +failable<bool> consume(JSONParser* parser, const list<string>& ilist, const js::JSContext& cx) { + if (isNil(ilist)) + return true; + JSString* jstr = JS_NewStringCopyZ(cx, c_str(car(ilist))); + if(!JS_ConsumeJSONText(cx, parser, JS_GetStringCharsZ(cx, jstr), (uint32)JS_GetStringLength(jstr))) + return mkfailure<bool>("JS_ConsumeJSONText failed"); + return consume(parser, cdr(ilist), cx); +} + +/** + * Convert a list of strings representing a JSON document to a list of values. + */ +const failable<list<value> > readJSON(const list<string>& ilist, const js::JSContext& cx) { + jsval val; + JSONParser* parser = JS_BeginJSONParse(cx, &val); + if(parser == NULL) + return mkfailure<list<value> >("JS_BeginJSONParse failed"); + + const failable<bool> consumed = consume(parser, ilist, cx); + + if(!JS_FinishJSONParse(cx, parser, JSVAL_NULL)) + return mkfailure<list<value> >("JS_FinishJSONParse failed"); + if(!hasContent(consumed)) + return mkfailure<list<value> >(consumed); + + return list<value>(js::jsValToValue(val, cx)); +} + +/** + * Context passed to the JSON write callback function. + */ +template<typename R> class WriteContext { +public: + WriteContext(const lambda<R(const string&, const R)>& reduce, const R& accum, const js::JSContext& cx) : cx(cx), reduce(reduce), accum(accum) { + } + const js::JSContext& cx; + const lambda<R(const string&, const R)> reduce; + R accum; +}; + +/** + * Called by JS_Stringify to write JSON out. + */ +template<typename R> JSBool writeCallback(const jschar *buf, uint32 len, void *data) { + WriteContext<R>& wcx = *(static_cast<WriteContext<R>*> (data)); + JSString* jstr = JS_NewUCStringCopyN(wcx.cx, buf, len); + char* cstr = JS_EncodeString(wcx.cx, jstr); + const string str(cstr, JS_GetStringLength(jstr)); + JS_free(wcx.cx, cstr); + wcx.accum = wcx.reduce(str, wcx.accum); + return JS_TRUE; +} + +/** + * Convert a list of values to a JSON document. + */ +template<typename R> const failable<R> writeJSON(const lambda<R(const string&, const R)>& reduce, const R& initial, const list<value>& l, const js::JSContext& cx) { + jsval val; + if (js::isJSArray(l)) + val = OBJECT_TO_JSVAL(valuesToJSElements(JS_NewArrayObject(cx, 0, NULL), l, 0, cx)); + else + val = OBJECT_TO_JSVAL(valuesToJSProperties(JS_NewObject(cx, NULL, NULL, NULL), l, cx)); + + WriteContext<R> wcx(reduce, initial, cx); + if (!JS_Stringify(cx, &val, NULL, INT_TO_JSVAL(1), writeCallback<R>, &wcx)) + return mkfailure<R>("JS_Stringify failed"); + return wcx.accum; +} + +/** + * Convert a list of values to a list of strings representing a JSON document. + */ +const failable<list<string> > writeJSON(const list<value>& l, const js::JSContext& cx) { + const failable<list<string> > ls = writeJSON<list<string>>(rcons<string>, list<string>(), valuesToElements(elementsToValues(l)), cx); + if (!hasContent(ls)) + return ls; + return reverse(list<string>(content(ls))); +} + +/** + * Convert a list of function + params to a JSON-RPC request. + */ +const failable<list<string> > jsonRequest(const value& id, const value& func, const value& params, js::JSContext& cx) { + const list<value> r = mklist<value>(mklist<value>("id", id), mklist<value>("method", string(func)), mklist<value>("params", params)); + return writeJSON(valuesToElements(r), cx); +} + +/** + * Convert a value to a JSON-RPC result. + */ +const failable<list<string> > jsonResult(const value& id, const value& val, js::JSContext& cx) { + return writeJSON(valuesToElements(mklist<value>(mklist<value>("id", id), mklist<value>("result", val))), cx); +} + +/** + * Convert a JSON-RPC result to a value. + */ +const failable<value> jsonResultValue(const list<string>& s, js::JSContext& cx) { + const failable<list<value> > jsres = json::readJSON(s, cx); + if (!hasContent(jsres)) + return mkfailure<value>(jsres); + const list<value> rval(cadr<value>(elementsToValues(content(jsres)))); + const value val = cadr(rval); + if (isList(val) && !js::isJSArray(val)) + return value(mklist<value>(val)); + return val; +} + +/** + * Convert a JSON payload to a list of values. + */ +const list<value> jsonValues(const list<value>& e) { + return elementsToValues(e); +} + +/** + * Return a portable function name from a JSON-RPC function name. + * Strip the ".", "system." and "Service." prefixes added by some JSON-RPC clients. + */ +const string funcName(const string& f) { + if (length(f) > 1 && find(f, ".", 0) == 0) + return c_str(f) + 1; + if (length(f) > 7 && find(f, "system.", 0) == 0) + return c_str(f) + 7; + if (length(f) > 8 && find(f, "Service.", 0) == 0) + return c_str(f) + 8; + return f; +} + +/** + * Returns a list of param values other than the id and method args from a list + * of key value pairs. + */ +const list<value> queryParams(const list<list<value> >& a) { + if (isNil(a)) + return list<value>(); + const list<value> p = car(a); + if (car(p) == value("id") || car(p) == value("method")) + return queryParams(cdr(a)); + return cons(cadr(p), queryParams(cdr(a))); +} + +} +} + +#endif /* tuscany_json_hpp */ |