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Diffstat (limited to 'runtime/prop.c')
-rw-r--r-- | runtime/prop.c | 247 |
1 files changed, 247 insertions, 0 deletions
diff --git a/runtime/prop.c b/runtime/prop.c new file mode 100644 index 00000000..804f3491 --- /dev/null +++ b/runtime/prop.c @@ -0,0 +1,247 @@ +/* prop.c - rsyslog's prop object + * + * This object is meant to support message properties that are stored + * seperately from the message. The main intent is to support properties + * that are "constant" during a period of time, so that many messages may + * contain a reference to the same property. It is important, though, that + * properties are destroyed when they are no longer needed. + * + * Please note that this is a performance-critical part of the software and + * as such we may use some methods in here which do not look elegant, but + * which are fast... + * + * Module begun 2009-06-17 by Rainer Gerhards + * + * Copyright 2009 Rainer Gerhards and Adiscon GmbH. + * + * This file is part of the rsyslog runtime library. + * + * The rsyslog runtime library is free software: you can redistribute it and/or modify + * it under the terms of the GNU Lesser General Public License as published by + * the Free Software Foundation, either version 3 of the License, or + * (at your option) any later version. + * + * The rsyslog runtime library 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 Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public License + * along with the rsyslog runtime library. If not, see <http://www.gnu.org/licenses/>. + * + * A copy of the GPL can be found in the file "COPYING" in this distribution. + * A copy of the LGPL can be found in the file "COPYING.LESSER" in this distribution. + */ + +#include "config.h" +#include <stdlib.h> +#include <assert.h> +#include <string.h> + +#include "rsyslog.h" +#include "obj.h" +#include "obj-types.h" +#include "unicode-helper.h" +#include "atomic.h" +#include "prop.h" + +/* static data */ +DEFobjStaticHelpers + + +/* Standard-Constructor + */ +BEGINobjConstruct(prop) /* be sure to specify the object type also in END macro! */ + pThis->iRefCount = 1; +ENDobjConstruct(prop) + + +/* destructor for the prop object */ +BEGINobjDestruct(prop) /* be sure to specify the object type also in END and CODESTART macros! */ + int currRefCount; +CODESTARTobjDestruct(prop) + currRefCount = ATOMIC_DEC_AND_FETCH(pThis->iRefCount); + if(currRefCount == 0) { + /* (only) in this case we need to actually destruct the object */ + if(pThis->len >= CONF_PROP_BUFSIZE) + free(pThis->szVal.psz); + } else { + pThis = NULL; /* tell framework NOT to destructing the object! */ + } +ENDobjDestruct(prop) + +/* set string, we make our own private copy! This MUST only be called BEFORE + * ConstructFinalize()! + */ +static rsRetVal SetString(prop_t *pThis, uchar *psz, int len) +{ + DEFiRet; + ISOBJ_TYPE_assert(pThis, prop); + if(pThis->len >= CONF_PROP_BUFSIZE) + free(pThis->szVal.psz); + pThis->len = len; + if(len < CONF_PROP_BUFSIZE) { + memcpy(pThis->szVal.sz, psz, len + 1); + } else { + CHKmalloc(pThis->szVal.psz = malloc(len + 1)); + memcpy(pThis->szVal.psz, psz, len + 1); + } + +finalize_it: + RETiRet; +} + + +/* get string length */ +static int GetStringLen(prop_t *pThis) +{ + return pThis->len; +} + + +/* get string */ +static rsRetVal GetString(prop_t *pThis, uchar **ppsz, int *plen) +{ + BEGINfunc + ISOBJ_TYPE_assert(pThis, prop); + if(pThis->len < CONF_PROP_BUFSIZE) { + *ppsz = pThis->szVal.sz; + } else { + *ppsz = pThis->szVal.psz; + } + *plen = pThis->len; + ENDfunc + return RS_RET_OK; +} + + +/* ConstructionFinalizer + * rgerhards, 2008-01-09 + */ +static rsRetVal +propConstructFinalize(prop_t __attribute__((unused)) *pThis) +{ + DEFiRet; + ISOBJ_TYPE_assert(pThis, prop); + RETiRet; +} + + +/* add a new reference. It is VERY IMPORTANT to call this function whenever + * the property is handed over to some entitiy that later call Destruct() on it. + */ +static rsRetVal AddRef(prop_t *pThis) +{ + ATOMIC_INC(pThis->iRefCount); + return RS_RET_OK; +} + + +/* this is a "do it all in one shot" function that creates a new property, + * assigns the provided string to it and finalizes the property. Among the + * convenience, it is alos (very, very) slightly faster. + * rgerhards, 2009-07-01 + */ +static rsRetVal CreateStringProp(prop_t **ppThis, uchar* psz, int len) +{ + DEFiRet; + propConstruct(ppThis); + SetString(*ppThis, psz, len); + propConstructFinalize(*ppThis); + RETiRet; +} + +/* another one-stop function, quite useful: it takes a property pointer and + * a string. If the string is already contained in the property, nothing happens. + * If the string is different (or the pointer NULL), the current property + * is destructed and a new one created. This can be used to get a specific + * name in those cases where there is a good chance that the property + * immediatly previously processed already contained the value we need - in + * which case we save us all the creation overhead by just reusing the already + * existing property). + * rgerhards, 2009-07-01 + */ +rsRetVal CreateOrReuseStringProp(prop_t **ppThis, uchar *psz, int len) +{ + uchar *pszPrev; + int lenPrev; + DEFiRet; + assert(ppThis != NULL); + + if(*ppThis == NULL) { + /* we need to create a property */ + CHKiRet(CreateStringProp(ppThis, psz, len)); + } else { + /* already exists, check if we can re-use it */ + GetString(*ppThis, &pszPrev, &lenPrev); + if(len != lenPrev && ustrcmp(psz, pszPrev)) { + /* different, need to discard old & create new one */ + propDestruct(ppThis); + CHKiRet(CreateStringProp(ppThis, psz, len)); + } /* else we can re-use the existing one! */ + } + +finalize_it: + RETiRet; +} + + +/* debugprint for the prop object */ +BEGINobjDebugPrint(prop) /* be sure to specify the object type also in END and CODESTART macros! */ +CODESTARTobjDebugPrint(prop) + dbgprintf("prop object %p - no further debug info implemented\n", pThis); +ENDobjDebugPrint(prop) + + +/* queryInterface function + * rgerhards, 2008-02-21 + */ +BEGINobjQueryInterface(prop) +CODESTARTobjQueryInterface(prop) + if(pIf->ifVersion != propCURR_IF_VERSION) { /* check for current version, increment on each change */ + ABORT_FINALIZE(RS_RET_INTERFACE_NOT_SUPPORTED); + } + + /* ok, we have the right interface, so let's fill it + * Please note that we may also do some backwards-compatibility + * work here (if we can support an older interface version - that, + * of course, also affects the "if" above). + */ + pIf->Construct = propConstruct; + pIf->ConstructFinalize = propConstructFinalize; + pIf->Destruct = propDestruct; + pIf->DebugPrint = propDebugPrint; + pIf->SetString = SetString; + pIf->GetString = GetString; + pIf->GetStringLen = GetStringLen; + pIf->AddRef = AddRef; + pIf->CreateStringProp = CreateStringProp; + pIf->CreateOrReuseStringProp = CreateOrReuseStringProp; + +finalize_it: +ENDobjQueryInterface(prop) + + +/* Exit the prop class. + * rgerhards, 2009-04-06 + */ +BEGINObjClassExit(prop, OBJ_IS_CORE_MODULE) /* class, version */ +// objRelease(errmsg, CORE_COMPONENT); +ENDObjClassExit(prop) + + +/* Initialize the prop class. Must be called as the very first method + * before anything else is called inside this class. + * rgerhards, 2008-02-19 + */ +BEGINObjClassInit(prop, 1, OBJ_IS_CORE_MODULE) /* class, version */ + /* request objects we use */ +// CHKiRet(objUse(errmsg, CORE_COMPONENT)); + + /* set our own handlers */ + OBJSetMethodHandler(objMethod_DEBUGPRINT, propDebugPrint); + OBJSetMethodHandler(objMethod_CONSTRUCTION_FINALIZER, propConstructFinalize); +ENDObjClassInit(prop) + +/* vi:set ai: + */ |