--- parser3/src/classes/op.C 2003/07/24 11:31:20 1.129 +++ parser3/src/classes/op.C 2003/11/19 11:00:32 1.136 @@ -5,12 +5,13 @@ Author: Alexandr Petrosian (http://paf.design.ru) */ -static const char* IDENT_OP_C="$Date: 2003/07/24 11:31:20 $"; +static const char* IDENT_OP_C="$Date: 2003/11/19 11:00:32 $"; #include "classes.h" #include "pa_vmethod_frame.h" #include "pa_common.h" +#include "pa_os.h" #include "pa_request.h" #include "pa_vint.h" #include "pa_sql_connection.h" @@ -48,13 +49,17 @@ static const String cache_data_name(CACH static const String exception_var_name(EXCEPTION_VAR_NAME); +// local defines + +#define CACHE_EXCEPTION_HANDLED_CACHE_NAME "cache" + // helpers -class Untaint_lang_name2enum: public Hash { +class Untaint_lang_name2enum: public Hash { public: Untaint_lang_name2enum() { #define ULN(name, LANG) \ - put(StringBody(name), (value_type)(String::L_##LANG)); + put(String::Body(name), (value_type)(String::L_##LANG)); ULN("as-is", AS_IS); ULN("optimized-as-is", AS_IS|String::L_OPTIMIZE_BIT); ULN("file-spec", FILE_SPEC); @@ -321,7 +326,7 @@ public: #endif static void _switch(Request& r, MethodParams& params) { Switch_data* data=new Switch_data(r, r.process_to_value(params[0])); - Temp_hash_value + Temp_hash_value switch_data_setter(r.classes_conf, switch_data_name, data); Value& cases_code=params.as_junction(1, "switch cases must be code"); @@ -374,12 +379,69 @@ static void _case(Request& r, MethodPara } } } +#ifndef DOXYGEN +struct Try_catch_result { + StringOrValue processed_code; + const String* exception_should_be_handled; + + Try_catch_result(): exception_should_be_handled(0) {} +}; +#endif + +/// used by ^try and ^cache, @returns $exception.handled[string] if any +template +static Try_catch_result try_catch(Request& r, + StringOrValue body_code(Request&, I), I info, + Value* catch_code) +{ + Try_catch_result result; + if(!catch_code) { + result.processed_code=body_code(r, info); + return result; + } + + // taking snapshot of try-context + Request_context_saver try_context(r); + try { + result.processed_code=body_code(r, info); + } catch(const Exception& e) { + Request_context_saver throw_context(r); // taking snapshot of throw-context [stack trace contains error] + Request::Exception_details details=r.get_details(e); + try_context.restore(); // restoring try-context to perform catch-code + + Junction* junction=catch_code->get_junction(); + Value* method_frame=junction->method_frame; + Value* saved_exception_var_value=method_frame->get_element(exception_var_name, *method_frame, false); + junction->method_frame->put_element(exception_var_name, &details.vhash, false); + result.processed_code=r.process(*catch_code); + + // retriving $exception.handled, restoring $exception var + Value* vhandled=details.vhash.hash().get(exception_handled_part_name); + junction->method_frame->put_element(exception_var_name, saved_exception_var_value, false); + + bool bhandled=false; + if(vhandled) { + if(vhandled->is_string()) { // not simple $exception.handled(1/0)? + result.exception_should_be_handled=vhandled->get_string(); // considering 'recovered' and let the caller recover + return result; + } + + bhandled=vhandled->as_bool(); + } + + if(!bhandled) { + throw_context.restore(); // restoring throw-context [exception were not handled] + rethrow; + } + } + return result; +} // cache-- // consts -const int DATA_STRING_SERIALIZED_VERSION=0x0004; +const int DATA_STRING_SERIALIZED_VERSION=0x0005; // helper types @@ -395,16 +457,25 @@ void cache_delete(const String& file_spe } #ifndef DOXYGEN -class Cache_data: public PA_Object { +struct Cache_scope { public: time_t expires; + const String* body_from_disk; }; struct Locked_process_and_cache_put_action_info { Request *r; - Cache_data *data; - Value* body_code; const String* evaluated_body; + Cache_scope *scope; + Value* body_code; Value* catch_code; + const String* processed_code; }; #endif + + + +static StringOrValue process_cache_body_code(Request& r, Value* body_code) { + return StringOrValue(&r.process_to_string(*body_code), 0); +} + /* @todo maybe network order worth spending some effort? don't bothering myself with network byte order, am not planning to be able to move resulting file across platforms @@ -414,31 +485,48 @@ static void locked_process_and_cache_put *static_cast(context); // body->process - info.evaluated_body=&info.r->process_to_string(*info.body_code); + Try_catch_result result=try_catch(*info.r, + process_cache_body_code, info.body_code, + info.catch_code); + + if(result.exception_should_be_handled) { + if(*result.exception_should_be_handled==CACHE_EXCEPTION_HANDLED_CACHE_NAME) { + if(const String* body_from_disk=info.scope->body_from_disk) // we have something old? + info.processed_code=body_from_disk; + else + throw Exception(0, + new String("$"EXCEPTION_VAR_NAME"."EXCEPTION_HANDLED_PART_NAME"["CACHE_EXCEPTION_HANDLED_CACHE_NAME"]"), + "fallback failed - there is no old cached body"); + } else + throw Exception("parser.runtime", + result.exception_should_be_handled, + "$"EXCEPTION_VAR_NAME"."EXCEPTION_HANDLED_PART_NAME" value must be " + "either boolean or string '"CACHE_EXCEPTION_HANDLED_CACHE_NAME"'"); + } else + info.processed_code=&result.processed_code.as_string(); // expiration time not spoiled by ^cache(0) or something? - if(info.data->expires > time(0)) { + if(info.scope->expires > time(0)) { // string -serialize> buffer - String::Cm serialized=info.evaluated_body->serialize( + String::Cm serialized=info.processed_code->serialize( sizeof(Data_string_serialized_prolog)); Data_string_serialized_prolog& prolog= *reinterpret_cast(serialized.str); prolog.version=DATA_STRING_SERIALIZED_VERSION; - prolog.expires=info.data->expires; + prolog.expires=info.scope->expires; // buffer -write> file write(f, serialized.str, serialized.length); } else // expired! - info.data->expires=0; // flag it so that could be easily checked by caller + info.scope->expires=0; // flag it so that could be easily checked by caller } const String* locked_process_and_cache_put(Request& r, Value& body_code, - Cache_data& data, - const String& file_spec) { - Locked_process_and_cache_put_action_info info={0}; - info.r=&r; - info.data=&data; - info.body_code=&body_code; + Value* catch_code, + Cache_scope& scope, + const String& file_spec) +{ + Locked_process_and_cache_put_action_info info={&r, &scope, &body_code, catch_code}; const String* result=file_write_action_under_lock( file_spec, @@ -446,13 +534,18 @@ const String* locked_process_and_cache_p false/*as_text*/, false/*do_append*/, false/*block*/, - false/*fail on lock problem*/) ? info.evaluated_body: 0; + false/*fail on lock problem*/) ? info.processed_code: 0; time_t now=time(0); - if(data.expires<=now) + if(scope.expires<=now) cache_delete(file_spec); return result; } -const String* cache_get(Request_charsets& charsets, const String& file_spec, time_t now) { +struct Cache_get_result { + const String* body; + bool expired; +} cache_get(Request_charsets& charsets, const String& file_spec, time_t now) { + Cache_get_result result={0}; + File_read_result file=file_read(charsets, file_spec, false/*as_text*/, 0, //no params @@ -463,16 +556,18 @@ const String* cache_get(Request_charsets Data_string_serialized_prolog& prolog= *reinterpret_cast(file.str); - String* result=new String; + String* body=new String; if( file.length>=sizeof(Data_string_serialized_prolog) - && prolog.version==DATA_STRING_SERIALIZED_VERSION - && prolog.expires > now - && result->deserialize(sizeof(Data_string_serialized_prolog), file.str, file.length)) - return result; + && prolog.version==DATA_STRING_SERIALIZED_VERSION) { + if(body->deserialize(sizeof(Data_string_serialized_prolog), file.str, file.length)) { + result.body=body; + result.expired=prolog.expires <= now; + } + } } - return 0; + return result; } static time_t as_expires(Request& r, MethodParams& params, int index, time_t now) { @@ -498,15 +593,15 @@ static void _cache(Request& r, MethodPar } // secods|expires date - Cache_data* data=static_cast(r.classes_conf.get(cache_data_name)); - if(!data) + Cache_scope* scope=static_cast(r.classes_conf.get(cache_data_name)); + if(!scope) throw Exception("parser.runtime", 0, "expire-time reducing instruction without cache"); time_t expires=as_expires(r, params, 0, now); - if(expires < data->expires) - data->expires=expires; + if(expires < scope->expires) + scope->expires=expires; return; } @@ -514,13 +609,16 @@ static void _cache(Request& r, MethodPar // file_spec, expires, body code const String& file_spec=r.absolute(params.as_string(0, "filespec must be string")); - Cache_data* data=new Cache_data; - Temp_hash_value - cache_data_setter(r.classes_conf, cache_data_name, data); - data->expires=as_expires(r, params, 1, now); - Value& body_code=params.as_junction(2, "body must be code"); + Cache_scope scope={as_expires(r, params, 1, now)}; - if(data->expires>now) { // valid 'expires' specified? try cached copy... + Temp_hash_value + cache_scope_setter(r.classes_conf, cache_data_name, &scope); + Value& body_code=params.as_junction(2, "body_code must be code"); + Value* catch_code=0; + if(params.count()>3) + catch_code=¶ms.as_junction(3, "catch_code must be code"); + + if(scope.expires>now) { // valid 'expires' specified? try cached copy... // hence we don't hope to have unary create/lockEX // we need some plan to live in a life like that, so... // worst races plan: @@ -538,24 +636,30 @@ static void _cache(Request& r, MethodPar // |lockSH succeeds; ... for(int retry=0; retry<2; retry++) { - if(const String* cached_body=cache_get(r.charsets, file_spec, now)) { // have cached copy? - // write it out - r.write_assign_lang(*cached_body); - // happy with it - return; + Cache_get_result cached=cache_get(r.charsets, file_spec, now); + if(cached.body) { // have cached copy + if(cached.expired) + scope.body_from_disk=cached.body; // storing for user to retrive it with ^cache[] + else // and it's not expired yet + { + // write it out + r.write_assign_lang(*cached.body); + // happy with it + return; + } } - // non-blocked lock; process; cache it - if(const String* processed_body= - locked_process_and_cache_put(r, body_code, *data, file_spec)) { - // write it out - r.write_assign_lang(*processed_body); - // happy with it - return; - } else { // somebody writing result right now - pa_sleep(0, 500000); // waiting half a second - retry=0; // prolonging our wait, than could cache_get it, without processing body_code - } + // non-blocked lock; process; cache it + if(const String* processed_body= + locked_process_and_cache_put(r, body_code, catch_code, scope, file_spec)) { + // write it out + r.write_assign_lang(*processed_body); + // happy with it + return; + } else { // somebody writing result right now + pa_sleep(0, 500000); // waiting half a second + retry=0; // prolonging our wait, than could cache_get it, without processing body_code + } } throw Exception(0, &file_spec, @@ -573,43 +677,24 @@ static void _cache(Request& r, MethodPar // never reached } - - -// also used in pa_request.C to pass param to @unhandled_exception - +static StringOrValue process_try_body_code(Request& r, Value* body_code) { + return r.process(*body_code); +} static void _try_operator(Request& r, MethodParams& params) { Value& body_code=params.as_junction(0, "body_code must be code"); Value& catch_code=params.as_junction(1, "catch_code must be code"); - StringOrValue result; - // taking snapshot of try-context - Request_context_saver try_context(r); - try { - result=r.process(body_code); - } catch(const Exception& e) { - Request::Exception_details details=r.get_details(e); - - Request_context_saver throw_context(r); // taking snapshot of throw-context [stack trace contains error] - try_context.restore(); // restoring try-context to perform catch-code - - Junction* junction=catch_code.get_junction(); - Value* method_frame=junction->method_frame; - Value* saved_exception_var_value=method_frame->get_element(exception_var_name, *method_frame, false); - junction->method_frame->put_element(exception_var_name, &details.vhash, false); - result=r.process(catch_code); - bool handled=false; - if(Value* value= - details.vhash.hash().get(exception_handled_part_name)) - handled=value->as_bool(); - junction->method_frame->put_element(exception_var_name, saved_exception_var_value, false); + Try_catch_result result=try_catch(r, + process_try_body_code, &body_code, + &catch_code); + + if(result.exception_should_be_handled) + throw Exception("parser.runtime", + result.exception_should_be_handled, + "catch block must set $exception.handled to some boolean value, not string"); - if(!handled) { - throw_context.restore(); // restoring throw-context [exception were not handled] - rethrow; - } - } - // write out result - r.write_pass_lang(result); + // write out processed body_code or catch_code + r.write_pass_lang(result.processed_code); } static void _throw_operator(Request& r, MethodParams& params) { @@ -639,7 +724,7 @@ static void _throw_operator(Request& r, :0; throw Exception(type, &source, "%s", comment?comment:""); } -} + } #if defined(WIN32) && defined(_DEBUG) # define PA_BPT @@ -691,9 +776,9 @@ VClassMAIN::VClassMAIN(): VClass() { add_native_method("connect", Method::CT_ANY, _connect, 2, 2); + // ^cache[file_spec](time){code}[{catch code}] time=0 no cache // ^cache[file_spec] delete cache - // ^cache[file_spec](time){code} time=0 no cache - add_native_method("cache", Method::CT_ANY, _cache, 1, 3); + add_native_method("cache", Method::CT_ANY, _cache, 1, 4); // switch