openVXI的缓存实现机制

DocumentParser的FetchDocument方法的声明如下：int DocumentParser::FetchDocument(const VXIchar * url,const VXIMapHolder & properties,VXIinetInterface * inet,VXIcacheInterface * cache,SimpleLogger & log,VXMLDocument & document,VXIMapHolder & docProperties,bool isDefaults,bool isRootApp,VXIbyte **content,VXIulong *size);很明显声明用到了VXIcacheInterface，但是继续阅读代码，却没有发现使用了参数cache。

就是参数中虽有VXIcacheInterface，但是函数中并没有用到。

浏览一下函数FetchDocument，里面有这样的注释：// (1) Load the VXML DTD for validation. This will override an externally// specified DTD if the user provides a link.// (2) Load the url into memory.// (3) Pull the document from cache.// (4) Not in cache; parse buffer into our VXML document representation// (5) Write the compiled form out to the cache.// (6) Parse was successful, process document. W e want only the top level <vxml> node.看一下// (3) Pull the document from cache.下面的代码，会发现是从一个叫DocumentStorageSingleton的变量里面。

DocumentStorageSingleton::Instance()->Retrieve(doc, buffer, bufSize, docURL.c_str())看一下DocumentStorageSingleton里面有个成员变量DOC_STORAGE storage;其实是map类型的。

注释所指的cache就是DocumentStorageSingleton。

也就是说DocumentParser用到的cache的功能是由DocumentSt orageSingleton实现的。

看一下VXIcache.h开头的注释：/* Abstract interface for accessing caching functionality, which* permits writing arbitrary data into the cache with a client* supplied key name, then retrieving that data from the cache one or* more times by reading against that key name. <p>** Normally the cache implementation can choose to discard the data* between the write and the read when necessary (due to running out* of cache space, etc.), but it is also possible for clients to lock* data in the cache to support built-in grammars and other data that* is explicitly provisioned by system administrators and thus must* not be removed unless by explicit system administrator command. <p>* The interface is a synchronous interface based on the ANSI/ISO C* standard file I/O interface. The client of the interface may use this in* an asynchronous manner by using non-blocking I/O operations,* creating threads, or by invoking this from a separate server* process. <p>** Typically the key name specified by clients will be the URL to the* source form of the data that is being written back, such as the URL* to the grammar text being used as the key name for the compiled* grammar. In the case where the VXIinet and VXIcache implementations* share the same underlying cache storage, it is thus necessary to* use prefixes or some other namespace mechanism to avoid collisions* with the cache entry for the original URL. <p>** However, the key names specified by clients may be very large in* some cases. This is most common when writing back data generated* from in-memory source text, such as when writing back the compiled* grammar for a VoiceXML document in-line grammar. One possible* VXIcache implementation approach is to use the MD5 algorithm as* used in HTTP message headers (specified in RFC 1321 with a full* implementation provided) to convert long key names to a 16 byte MD5* value for indexing purposes, using Base64 encoding to convert the* binary MD5 value to ASCII text if desired (as done in HTTP message* headers). <p>** There is one cache interface per thread/line. <p>*/大意是说可以放进去任意的数据，并可以用URL检索出来。

URL如果太长，会用md5和base64处理。

那c ache模块中的功能在那儿用到了那？在VXIclient.cpp的第1088行（左右）有下面的内容：/* Create the cache resource. The cache resource will be used bythe recognizer and prompting components for caching of computeddata like compiled grammars and text-to-speech prompts. */cacheResult = SBcacheCreateResource(newPlatform->VXIlog, &newPlatform->VXIcache);注释的意思是cache是recognizer和prompting 组件用到的。

在VXIprompt和VXIrec中，仅仅有VXIpromptResult VXIpromptCreateResource (VXIlogInterface *log,VXIinetInterface *inet,VXIcacheInterface *cache,VXIpromptInterface **prompt)和VXIREC_API VXIrecResult VXIrecCreateResource(VXIlogInterface *log,VXIinetInterface *inet,VXIcacheInterface *cache,VXIpromptInterface *prompt,VXItelInterface *tel,VXIrecInterface **rec)用到了，而且函数里面参数cache并没有用到，感觉要实现者自己写代码吧。

代码没再继续往下看。

OpenVXI没有保存里面的内容，需要自己实现。

示例代码如下，粗体代码为手动添加的部分。

你需要做的是，备份VXIprompt模块下的VXIprompt.cpp，然后把下面的代码替换掉原来VXIprompt下面VXIprompt. cpp里面的内容，然后编译即可（如果编译有错误，去掉[B][/B]，这是编辑帖子的时候加的）：/****************License************************************************* Vocalocity OpenVXI* Copyright (C) 2004-2005 by Vocalocity, Inc. All Rights Reserved.* This program is free software; you can redistribute it and/or* modify it under the terms of the GNU General Public License* as published by the Free Software Foundation; either version 2* of the License, or (at your option) any later version.** This program is distributed in the hope that it will be useful,* but WITHOUT ANY WARRANTY; without even the implied warranty of* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the* GNU General Public License for more details.** You should have received a copy of the GNU General Public License* along with this program; if not, write to the Free Software* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.* Vocalocity, the Vocalocity logo, and VocalOS are trademarks or* registered trademarks of Vocalocity, Inc.* OpenVXI is a trademark of Scansoft, Inc. and used under license* by Vocalocity.***********************************************************************/#include <cstdio>#include <string>#include <cstring>#define VXIstrcmp wcscmp#include "..\include\VXIvalue.h"#include "..\include\VXIpromptAPI.h"#include "../swichar/include/swistring.h"// Global for the base diagnostic tag ID//static VXIunsigned gblDiagLogBase = 0;// Constants for diagnostic logging tags//static const VXIunsigned DIAG_TAG_PROMPTING = 1;static const VXIunsigned DIAG_TAG_PREFETCHING = 2;// VXIprompt implementation of the VXIprompt interface//#include <list>using namespace std;extern "C" {struct VXIpromptImpl {// Base interface, must be firstVXIpromptInterfaceEx intf;// Log interface for this resourceVXIlogInterface *log;// Internet fetch interface for this resourceVXIinetInterface *inet;list<vxistring> ttstexts;};}// A few conversion functions...static inline VXIpromptImpl * ToVXIpromptImpl(VXIpromptInterface * i) { return reinterpret_cast<VXIpromptImpl *>(i); }static inline VXIpromptImpl * ToVXIpromptImpl(VXIpromptInterfaceEx * i) { return reinterpret_cast<VXIpromptImpl *>(i); }/********************************************************* Utility functions********************************************************//*** Log an error*/static VXIlogResult Error(VXIpromptImpl *impl, VXIunsigned errorID,const VXIchar *format, ...){VXIlogResult rc;va_list arguments;if ((! impl) || (! impl->log))return VXIlog_RESULT_NON_FATAL_ERROR;if (format) {va_start(arguments, format);rc = (*impl->log->VError)(impl->log, COMPANY_DOMAIN L".VXIprompt",errorID, format, arguments);va_end(arguments);} else {rc = (*impl->log->Error)(impl->log, COMPANY_DOMAIN L".VXIprompt",errorID, NULL);}return rc;}/*** Log a diagnostic message*/static VXIlogResult Diag(VXIpromptImpl *impl, VXIunsigned tag,const VXIchar *subtag, const VXIchar *format, ...){VXIlogResult rc;va_list arguments;if ((! impl) || (! impl->log))return VXIlog_RESULT_NON_FATAL_ERROR;if (format) {va_start(arguments, format);rc = (*impl->log->VDiagnostic)(impl->log, tag + gblDiagLogBase, subtag, format, arguments);va_end(arguments);} else {rc = (*impl->log->Diagnostic)(impl->log, tag + gblDiagLogBase, subtag, NULL);}return rc;}/********************************************************* Method routines for VXIpromptInterface structure********************************************************/// Get the VXIprompt interface version supported//static VXIint32 VXIpromptGetVersion(void){return VXI_CURRENT_VERSION;}// Get the implementation name//static const VXIchar* VXIpromptGetImplementationName(void){static const VXIchar IMPLEMENTATION_NAME[] = COMPANY_DOMAIN L".VXIprompt"; return IMPLEMENTATION_NAME;}// Begin a session//staticVXIpromptResult VXIpromptBeginSession(VXIpromptInterface * pThis, VXIMap *) {return VXIprompt_RESULT_SUCCESS;}// End a session//staticVXIpromptResult VXIpromptEndSession(VXIpromptInterface *pThis, VXIMap *) {return VXIprompt_RESULT_SUCCESS;}// Start playing queued prompts. This call is non-blocking.//static VXIpromptResult VXIpromptPlay(VXIpromptInterface * vxip){VXIpromptImpl *impl = ToVXIpromptImpl(vxip);vxistring tts;if( impl->ttstexts.size()>0){tts=impl->ttstexts.front();impl->ttstexts.pop_front();printf("****************VXIpromptPlay语音内容********************\n");for(int in=0;in<tts.length();in++){printf("%c",tts[in]);[/B]}printf("\n****************VXIpromptPlay语音内容********************\n"); };Diag(impl, DIAG_TAG_PROMPTING, NULL, L"Playing queued prompts");return VXIprompt_RESULT_SUCCESS;}// Start the special play of a filler prompt. This call is non-blocking.//staticVXIpromptResult VXIpromptPlayFiller(VXIpromptInterface * vxip,const VXIchar *type,const VXIchar *src,const VXIchar *text,const VXIMap* properties,VXIlong minPlayMsec){return VXIprompt_RESULT_SUCCESS;}staticVXIpromptResult VXIpromptPrefetch(VXIpromptInterface * vxip,const VXIchar *type,const VXIchar *src,const VXIchar *text,const VXIMap* properties){VXIpromptImpl *impl = ToVXIpromptImpl(vxip);Diag(impl, DIAG_TAG_PREFETCHING, L"VXIpromptPrefetch", L"%s",(text ? text : L"NULL"));//printf("************%s************%s",src,text);return VXIprompt_RESULT_SUCCESS;}// Queue prompt for playing. This call is non-blocking. The prompt// is not played until VXIpromptPlay( ) is called.//staticVXIpromptResult VXIpromptQueue(VXIpromptInterface* vxip,const VXIchar *raw_type,const VXIchar *raw_src, /* no longer used */const VXIchar *raw_text,const VXIMap *properties){VXIpromptImpl *impl = ToVXIpromptImpl(vxip);vxistring type(L""), text(L"");if (raw_type)type = raw_type;if (raw_text){text = raw_text;}// Handle the resolved information to queue.if (text.empty())return VXIprompt_RESULT_INVALID_ARGUMENT;// currently, vxi only queues SSMLif (type == VXI_MIME_SSML) {vxistring bargein;const VXIValue *val = VXIMapGetProperty(properties, L"bargein");if (val != NULL)bargein = VXIStringCStr(reinterpret_cast<const VXIString*>(val));vxistring bargeintype;val = VXIMapGetProperty(properties, L"bargeintype");if (val != NULL)bargeintype = VXIStringCStr(reinterpret_cast<const VXIString*>(val));impl->ttstexts.push_back(text);printf("****************语音内容********************\n");for(int in=0;in<text.length();in++){printf("%c",text[in]);}printf("\n****************语音内容********************\n");Diag(impl, DIAG_TAG_PROMPTING, NULL, L"Queuing TTS: bargein=%s, bargeintype=%s, ssml=%s", bargein.c_str(), bargeintype.c_str(), text.c_str());}else {Diag(impl, DIAG_TAG_PROMPTING, NULL,L"Queuing Unknown type text (%s): %s" , type.c_str(), text.c_str());return VXIprompt_RESULT_UNSUPPORTED;}}// Wait until all queued prompts finish playing.//static VXIpromptResult VXIpromptWait(VXIpromptInterface* vxip,VXIpromptResult* playResult){VXIpromptImpl *impl = ToVXIpromptImpl(vxip);Diag(impl, DIAG_TAG_PROMPTING, NULL,L"%s" , L"VXIpromptWait");*playResult = VXIprompt_RESULT_SUCCESS;return VXIprompt_RESULT_SUCCESS;}// Stop the current playing prompt.//static VXIpromptResult VXIpromptStop (VXIpromptInterfaceEx *prompt) {if (prompt == NULL)return VXIprompt_RESULT_INVALID_ARGUMENT;VXIpromptImpl* promptImpl = reinterpret_cast<VXIpromptImpl*>(prompt); return VXIprompt_RESULT_SUCCESS;}/******************************************************** Global init and factory methods*******************************************************/VXIPROMPT_API VXIpromptResult VXIpromptInit (VXIlogInterface *log,VXIunsigned diagLogBase,const VXIVector *resources,VXIMap *args){if (! log) return VXIprompt_RESULT_INVALID_ARGUMENT;gblDiagLogBase = diagLogBase;return VXIprompt_RESULT_SUCCESS;}VXIPROMPT_API VXIpromptResult VXIpromptShutDown (VXIlogInterface *log) {if (! log) return VXIprompt_RESULT_INVALID_ARGUMENT;}VXIPROMPT_APIVXIpromptResult VXIpromptCreateResource (VXIlogInterface *log,VXIinetInterface *inet,VXIcacheInterface *cache,VXIpromptInterface **prompt){if ((! log) || (! inet)) return VXIprompt_RESULT_INVALID_ARGUMENT;VXIpromptImpl* pp = new VXIpromptImpl();if (pp == NULL) return VXIprompt_RESULT_OUT_OF_MEMORY;pp->log = log;pp->inet = inet;pp->intf.vxiprompt.GetVersion = VXIpromptGetVersion;pp->intf.vxiprompt.GetImplementationName = VXIpromptGetImplementationName; pp->intf.vxiprompt.BeginSession = VXIpromptBeginSession;pp->intf.vxiprompt.EndSession = VXIpromptEndSession;pp->intf.vxiprompt.Play = VXIpromptPlay;pp->intf.vxiprompt.PlayFiller = VXIpromptPlayFiller;pp->intf.vxiprompt.Prefetch = VXIpromptPrefetch;pp->intf.vxiprompt.Queue = VXIpromptQueue;pp->intf.vxiprompt.Wait = VXIpromptWait;pp->intf.Stop = VXIpromptStop;*prompt = &pp->intf.vxiprompt;return VXIprompt_RESULT_SUCCESS;}VXIPROMPT_APIVXIpromptResult VXIpromptDestroyResource (VXIpromptInterface **prompt){if (prompt == NULL || *prompt == NULL)return VXIprompt_RESULT_INVALID_ARGUMENT;VXIpromptImpl* promptImpl = reinterpret_cast<VXIpromptImpl*>(*prompt);delete promptImpl;*prompt = NULL;return VXIprompt_RESULT_SUCCESS;}。