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-rw-r--r-- | sca-cpp/branches/cpp-contrib/modules/json/json.hpp | 403 |
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diff --git a/sca-cpp/branches/cpp-contrib/modules/json/json.hpp b/sca-cpp/branches/cpp-contrib/modules/json/json.hpp new file mode 100644 index 0000000000..1d966d3f67 --- /dev/null +++ b/sca-cpp/branches/cpp-contrib/modules/json/json.hpp @@ -0,0 +1,403 @@ +/* + * 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. + */ + +#define XP_UNIX +#include <jsapi.h> +#include "string.hpp" +#include "list.hpp" +#include "value.hpp" +#include "element.hpp" +#include "monad.hpp" + +namespace tuscany { +namespace json { + +/** + * Report JSON errors. + */ +void reportError(unused JSContext *cx, const char *message, JSErrorReport *report) { + cerr << (const char*)(report->filename? report->filename : "<no filename>") << ":" + << (int)report->lineno << ":" << message << endl; +} + +/** + * Encapsulates a JavaScript runtime. Shared by multiple threads in + * a process. + */ +class JSONRuntime { +public: + JSONRuntime() { + // Create JS runtime + rt = JS_NewRuntime(8L * 1024L * 1024L); + if(rt == NULL) + cleanup(); + } + + operator JSRuntime*() const { + return rt; + } +private: + bool cleanup() { + if(rt != NULL) { + JS_DestroyRuntime(rt); + rt = NULL; + } + JS_ShutDown(); + return true; + } + + JSRuntime* rt; +} jsRuntime; + +JSClass jsGlobalClass = { "global", JSCLASS_GLOBAL_FLAGS, JS_PropertyStub, JS_PropertyStub, JS_PropertyStub, + JS_PropertyStub, JS_EnumerateStub, JS_ResolveStub, JS_ConvertStub, JS_FinalizeStub, JSCLASS_NO_OPTIONAL_MEMBERS}; + +/** + * Represents a JavaScript context. Create one per thread. + */ +class JSONContext { +public: + JSONContext() { + // Create JS context + cx = JS_NewContext(jsRuntime, 8192); + if(cx == NULL) + return; + JS_SetOptions(cx, JSOPTION_VAROBJFIX); + JS_SetVersion(cx, JSVERSION_DEFAULT); + JS_SetErrorReporter(cx, reportError); + + // Create global JS object + global = JS_NewObject(cx, &jsGlobalClass, NULL, NULL); + if(global == NULL) { + cleanup(); + return; + } + + // Populate global object with the standard globals, like Object and Array + if(!JS_InitStandardClasses(cx, global)) { + cleanup(); + return; + } + } + + ~JSONContext() { + cleanup(); + } + + operator JSContext*() const { + return cx; + } + + JSObject* getGlobal() const { + return global; + } + +private: + bool cleanup() { + if(cx != NULL) { + JS_DestroyContext(cx); + cx = NULL; + } + return true; + } + + JSContext* cx; + JSObject* global; +}; + +/** + * Returns true if a list represents a JS array. + */ +const bool isJSArray(const list<value>& l) { + if(isNil(l)) + return true; + const value v = car(l); + if (isSymbol(v)) + return false; + if(isList(v)) { + if(!isNil((list<value>)v) && isSymbol(car<value>(v))) + return false; + } + return true; +} + +/** + * Converts JS properties to values. + */ +const list<value> jsPropertiesToValues(const list<value>& propertiesSoFar, JSObject* o, JSObject* i, const JSONContext& cx) { + + const value jsValToValue(const jsval& jsv, const JSONContext& cx); + + jsid id; + if(!JS_NextProperty(cx, i, &id) || id == JSVAL_VOID) + return propertiesSoFar; + jsval jsv; + if(!JS_GetPropertyById(cx, o, id, &jsv)) + return propertiesSoFar; + const value val = jsValToValue(jsv, cx); + + jsval idv; + JS_IdToValue(cx, id, &idv); + if(JSVAL_IS_STRING(idv)) { + const string name = JS_GetStringBytes(JSVAL_TO_STRING(idv)); + if (substr(name, 0, 1) == atsign) + return jsPropertiesToValues(cons<value>(mklist<value>(attribute, c_str(substr(name, 1)), val), propertiesSoFar), o, i, cx); + if (isList(val) && !isJSArray(val)) + return jsPropertiesToValues(cons<value>(cons<value>(element, cons<value>(c_str(name), list<value>(val))), propertiesSoFar), o, i, cx); + return jsPropertiesToValues(cons<value> (mklist<value> (element, c_str(name), val), propertiesSoFar), o, i, cx); + } + return jsPropertiesToValues(cons(val, propertiesSoFar), o, i, cx); +} + +/** + * Converts a JS val to a value. + */ +const value jsValToValue(const jsval& jsv, const JSONContext& cx) { + switch(JS_TypeOfValue(cx, jsv)) { + case JSTYPE_STRING: { + return value(string(JS_GetStringBytes(JSVAL_TO_STRING(jsv)))); + } + case JSTYPE_BOOLEAN: { + return value((bool)JSVAL_TO_BOOLEAN(jsv)); + } + case JSTYPE_NUMBER: { + jsdouble jsd; + JS_ValueToNumber(cx, jsv, &jsd); + return value((double)jsd); + } + case JSTYPE_OBJECT: { + JSObject* o = JSVAL_TO_OBJECT(jsv); + JSObject* i = JS_NewPropertyIterator(cx, o); + if(i == NULL) + return value(list<value> ()); + const value pv = jsPropertiesToValues(list<value> (), o, i, cx); + return pv; + } + default: { + return value(); + } + } +} + +/** + * Consumes JSON strings and populates a JS object. + */ +failable<bool> consume(JSONParser* parser, const list<string>& ilist, const JSONContext& cx) { + if (isNil(ilist)) + return true; + JSString* jstr = JS_NewStringCopyZ(cx, c_str(car(ilist))); + if(!JS_ConsumeJSONText(cx, parser, JS_GetStringChars(jstr), 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 JSONContext& 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> >(reason(consumed)); + + return list<value>(jsValToValue(val, cx)); +} + +/** + * Converts a list of values to JS array elements. + */ +JSObject* valuesToJSElements(JSObject* a, const list<value>& l, int i, const JSONContext& cx) { + const jsval valueToJSVal(const value& val, const JSONContext& cx); + if (isNil(l)) + return a; + jsval pv = valueToJSVal(car(l), cx); + JS_SetElement(cx, a, i, &pv); + return valuesToJSElements(a, cdr(l), ++i, cx); +} + +/** + * Converts a value to a JS val. + */ +const jsval valueToJSVal(const value& val, const JSONContext& cx) { + JSObject* valuesToJSProperties(JSObject* o, const list<value>& l, const JSONContext& cx); + + switch(type(val)) { + case value::String: + case value::Symbol: { + return STRING_TO_JSVAL(JS_NewStringCopyZ(cx, c_str((string)val))); + } + case value::Bool: { + return BOOLEAN_TO_JSVAL((bool)val); + } + case value::Number: { + return DOUBLE_TO_JSVAL(JS_NewDouble(cx, (double)val)); + } + case value::List: { + if (isJSArray(val)) + return OBJECT_TO_JSVAL(valuesToJSElements(JS_NewArrayObject(cx, 0, NULL), val, 0, cx)); + return OBJECT_TO_JSVAL(valuesToJSProperties(JS_NewObject(cx, NULL, NULL, NULL), val, cx)); + } + default: { + return JSVAL_VOID; + } + } +} + +/** + * Converts a list of values to JS properties. + */ +JSObject* valuesToJSProperties(JSObject* o, const list<value>& l, const JSONContext& cx) { + if (isNil(l)) + return o; + + // Write an attribute + const value token(car(l)); + + if (isTaggedList(token, attribute)) { + jsval pv = valueToJSVal(attributeValue(token), cx); + JS_SetProperty(cx, o, c_str(atsign + string(attributeName(token))), &pv); + + } else if (isTaggedList(token, element)) { + + // Write the value of an element + if (elementHasValue(token)) { + jsval pv = valueToJSVal(elementValue(token), cx); + JS_SetProperty(cx, o, c_str(string(elementName(token))), &pv); + + } else { + + // Write a parent element + JSObject* child = JS_NewObject(cx, NULL, NULL, NULL); + jsval pv = OBJECT_TO_JSVAL(child); + JS_SetProperty(cx, o, c_str(string(elementName(token))), &pv); + + // Write its children + valuesToJSProperties(child, elementChildren(token), cx); + } + } + + // Go on + return valuesToJSProperties(o, cdr(l), 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 JSONContext& cx) : cx(cx), reduce(reduce), accum(accum) { + } + const JSONContext& 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); + wcx.accum = wcx.reduce(string(JS_GetStringBytes(jstr), JS_GetStringLength(jstr)), 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 JSONContext& cx) { + jsval 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, JSVAL_NULL, 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 JSONContext& cx) { + const failable<list<string> > ls = writeJSON<list<string>>(rcons<string>, list<string>(), 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, json::JSONContext& 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, JSONContext& 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, JSONContext& cx) { + const failable<list<value> > jsres = json::readJSON(s, cx); + if (!hasContent(jsres)) + return mkfailure<value>(reason(jsres)); + const list<value> rval(cadr<value>(elementsToValues(content(jsres)))); + const value val = cadr(rval); + if (isList(val) && !isJSArray(val)) + return value(mklist<value>(val)); + return val; +} + +/** + * 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) > 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; +} + +} +} + +#endif /* tuscany_json_hpp */ |