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Annotation of sbbs/include/mozilla/nspr/prcountr.h, revision 1.1

1.1     ! root        1: /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
        !             2: /* 
        !             3:  * The contents of this file are subject to the Mozilla Public
        !             4:  * License Version 1.1 (the "License"); you may not use this file
        !             5:  * except in compliance with the License. You may obtain a copy of
        !             6:  * the License at http://www.mozilla.org/MPL/
        !             7:  * 
        !             8:  * Software distributed under the License is distributed on an "AS
        !             9:  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
        !            10:  * implied. See the License for the specific language governing
        !            11:  * rights and limitations under the License.
        !            12:  * 
        !            13:  * The Original Code is the Netscape Portable Runtime (NSPR).
        !            14:  * 
        !            15:  * The Initial Developer of the Original Code is Netscape
        !            16:  * Communications Corporation.  Portions created by Netscape are 
        !            17:  * Copyright (C) 1998-2000 Netscape Communications Corporation.  All
        !            18:  * Rights Reserved.
        !            19:  * 
        !            20:  * Contributor(s):
        !            21:  * 
        !            22:  * Alternatively, the contents of this file may be used under the
        !            23:  * terms of the GNU General Public License Version 2 or later (the
        !            24:  * "GPL"), in which case the provisions of the GPL are applicable 
        !            25:  * instead of those above.  If you wish to allow use of your 
        !            26:  * version of this file only under the terms of the GPL and not to
        !            27:  * allow others to use your version of this file under the MPL,
        !            28:  * indicate your decision by deleting the provisions above and
        !            29:  * replace them with the notice and other provisions required by
        !            30:  * the GPL.  If you do not delete the provisions above, a recipient
        !            31:  * may use your version of this file under either the MPL or the
        !            32:  * GPL.
        !            33:  */
        !            34: 
        !            35: #ifndef prcountr_h___
        !            36: #define prcountr_h___
        !            37: 
        !            38: /*----------------------------------------------------------------------------
        !            39: ** prcountr.h -- NSPR Instrumentation counters
        !            40: **
        !            41: ** The NSPR Counter Feature provides a means to "count
        !            42: ** something." Counters can be dynamically defined, incremented,
        !            43: ** decremented, set, and deleted under application program
        !            44: ** control.
        !            45: **                                                                                    
        !            46: ** The Counter Feature is intended to be used as instrumentation,                  
        !            47: ** not as operational data. If you need a counter for operational                  
        !            48: ** data, use native integral types.                                                
        !            49: **                                                                                    
        !            50: ** Counters are 32bit unsigned intergers. On overflow, a counter                   
        !            51: ** will wrap. No exception is recognized or reported.                              
        !            52: **                                                                                 
        !            53: ** A counter can be dynamically created using a two level naming
        !            54: ** convention. A "handle" is returned when the counter is
        !            55: ** created. The counter can subsequently be addressed by its
        !            56: ** handle. An API is provided to get an existing counter's handle
        !            57: ** given the names with  which it was originally created. 
        !            58: ** Similarly, a counter's name can be retrieved given its handle.
        !            59: ** 
        !            60: ** The counter naming convention is a two-level hierarchy. The
        !            61: ** QName is the higher level of the hierarchy; RName is the
        !            62: ** lower level. RNames can be thought of as existing within a
        !            63: ** QName. The same RName can exist within multiple QNames. QNames
        !            64: ** are unique. The NSPR Counter is not a near-zero overhead
        !            65: ** feature. Application designers should be aware of 
        !            66: ** serialization issues when using the Counter API. Creating a
        !            67: ** counter locks a large asset, potentially causing a stall. This
        !            68: ** suggest that applications should create counters at component
        !            69: ** initialization, for example, and not create and destroy them
        !            70: ** willy-nilly. ... You have been warned.
        !            71: ** 
        !            72: ** Incrementing and Adding to counters uses atomic operations.
        !            73: ** The performance of these operations will vary from platform
        !            74: ** to platform. On platforms where atomic operations are not
        !            75: ** supported the overhead may be substantial.
        !            76: ** 
        !            77: ** When traversing the counter database with FindNext functions,
        !            78: ** the instantaneous values of any given counter is that at the
        !            79: ** moment of extraction. The state of the entire counter database
        !            80: ** may not be viewed as atomic.
        !            81: ** 
        !            82: ** The counter interface may be disabled (No-Op'd) at compile
        !            83: ** time. When DEBUG is defined at compile time, the Counter
        !            84: ** Feature is compiled into NSPR and applications invoking it.
        !            85: ** When DEBUG is not defined, the counter macros compile to
        !            86: ** nothing. To force the Counter Feature to be compiled into an
        !            87: ** optimized build, define FORCE_NSPR_COUNTERS at compile time
        !            88: ** for both NSPR and the application intending to use it.
        !            89: ** 
        !            90: ** Application designers should use the macro form of the Counter
        !            91: ** Feature methods to minimize performance impact in optimized
        !            92: ** builds. The macros normally compile to nothing on optimized
        !            93: ** builds.
        !            94: ** 
        !            95: ** Application designers should be aware of the effects of
        !            96: ** debug and optimized build differences when using result of the
        !            97: ** Counter Feature macros in expressions.
        !            98: ** 
        !            99: ** The Counter Feature is thread-safe and SMP safe.
        !           100: ** 
        !           101: ** /lth. 09-Jun-1998.
        !           102: */
        !           103: 
        !           104: #include "prtypes.h"
        !           105: 
        !           106: PR_BEGIN_EXTERN_C
        !           107: 
        !           108: /*
        !           109: ** Opaque counter handle type.
        !           110: ** ... don't even think of looking in here.
        !           111: **
        !           112: */
        !           113: typedef void *  PRCounterHandle;
        !           114: 
        !           115: #define PRCOUNTER_NAME_MAX 31
        !           116: #define PRCOUNTER_DESC_MAX 255
        !           117: 
        !           118: 
        !           119: 
        !           120: /* -----------------------------------------------------------------------
        !           121: ** FUNCTION: PR_DEFINE_COUNTER() -- Define a PRCounterHandle
        !           122: ** 
        !           123: ** DESCRIPTION: PR_DEFINE_COUNTER() is used to define a counter
        !           124: ** handle.
        !           125: ** 
        !           126: */
        !           127: #define PR_DEFINE_COUNTER(name) PRCounterHandle name
        !           128: 
        !           129: /* -----------------------------------------------------------------------
        !           130: ** FUNCTION: PR_INIT_COUNTER_HANDLE() -- Set the value of a PRCounterHandle
        !           131: ** 
        !           132: ** DESCRIPTION: 
        !           133: ** PR_INIT_COUNTER_HANDLE() sets the value of a PRCounterHandle
        !           134: ** to value.
        !           135: ** 
        !           136: */
        !           137: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           138: #define PR_INIT_COUNTER_HANDLE(handle,value)\
        !           139:     (handle) = (PRCounterHandle)(value)
        !           140: #else
        !           141: #define PR_INIT_COUNTER_HANDLE(handle,value)
        !           142: #endif
        !           143: 
        !           144: /* -----------------------------------------------------------------------
        !           145: ** FUNCTION: PR_CreateCounter() -- Create a counter
        !           146: ** 
        !           147: ** DESCRIPTION: PR_CreateCounter() creates a counter object and
        !           148: ** initializes it to zero.
        !           149: ** 
        !           150: ** The macro form takes as its first argument the name of the
        !           151: ** PRCounterHandle to receive the handle returned from
        !           152: ** PR_CreateCounter().
        !           153: ** 
        !           154: ** INPUTS:
        !           155: **  qName: The QName for the counter object. The maximum length
        !           156: ** of qName is defined by PRCOUNTER_NAME_MAX
        !           157: ** 
        !           158: **  rName: The RName for the counter object. The maximum length
        !           159: ** of qName is defined by PRCOUNTER_NAME_MAX
        !           160: ** 
        !           161: **  descrioption: The description of the counter object. The
        !           162: ** maximum length of description is defined by
        !           163: ** PRCOUNTER_DESC_MAX.
        !           164: ** 
        !           165: ** OUTPUTS:
        !           166: ** 
        !           167: ** RETURNS:
        !           168: **  PRCounterHandle.
        !           169: ** 
        !           170: ** RESTRICTIONS:
        !           171: ** 
        !           172: */
        !           173: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           174: #define PR_CREATE_COUNTER(handle,qName,rName,description)\
        !           175:    (handle) = PR_CreateCounter((qName),(rName),(description))
        !           176: #else
        !           177: #define PR_CREATE_COUNTER(handle,qName,rName,description)
        !           178: #endif
        !           179: 
        !           180: NSPR_API(PRCounterHandle) 
        !           181:    PR_CreateCounter( 
        !           182:        const char *qName, 
        !           183:        const char *rName, 
        !           184:         const char *description 
        !           185: );
        !           186: 
        !           187: /* -----------------------------------------------------------------------
        !           188: ** FUNCTION: PR_DestroyCounter() -- Destroy a counter object.
        !           189: ** 
        !           190: ** DESCRIPTION: PR_DestroyCounter() removes a counter and
        !           191: ** unregisters its handle from the counter database.
        !           192: ** 
        !           193: ** INPUTS:
        !           194: **  handle: the PRCounterHandle of the counter to be destroyed.
        !           195: ** 
        !           196: ** OUTPUTS: 
        !           197: **  The counter is destroyed.
        !           198: ** 
        !           199: ** RETURNS: void
        !           200: ** 
        !           201: ** RESTRICTIONS:
        !           202: ** 
        !           203: */
        !           204: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           205: #define PR_DESTROY_COUNTER(handle) PR_DestroyCounter((handle))
        !           206: #else
        !           207: #define PR_DESTROY_COUNTER(handle)
        !           208: #endif
        !           209: 
        !           210: NSPR_API(void) 
        !           211:    PR_DestroyCounter( 
        !           212:        PRCounterHandle handle 
        !           213: );
        !           214: 
        !           215: 
        !           216: /* -----------------------------------------------------------------------
        !           217: ** FUNCTION: PR_GetCounterHandleFromName() -- Retreive a
        !           218: ** counter's handle give its name.
        !           219: ** 
        !           220: ** DESCRIPTION: PR_GetCounterHandleFromName() retreives a
        !           221: ** counter's handle from the counter database, given the name
        !           222: ** the counter was originally created with.
        !           223: ** 
        !           224: ** INPUTS:
        !           225: **  qName: Counter's original QName.
        !           226: **  rName: Counter's original RName.
        !           227: ** 
        !           228: ** OUTPUTS:
        !           229: ** 
        !           230: ** RETURNS: 
        !           231: **  PRCounterHandle or PRCounterError.
        !           232: ** 
        !           233: ** RESTRICTIONS:
        !           234: ** 
        !           235: */
        !           236: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           237: #define PR_GET_COUNTER_HANDLE_FROM_NAME(handle,qName,rName)\
        !           238:     (handle) = PR_GetCounterHandleFromName((qName),(rName))
        !           239: #else
        !           240: #define PR_GET_COUNTER_HANDLE_FROM_NAME(handle,qName,rName)
        !           241: #endif
        !           242: 
        !           243: NSPR_API(PRCounterHandle) 
        !           244:    PR_GetCounterHandleFromName( 
        !           245:        const char *qName, 
        !           246:        const char *rName 
        !           247: );
        !           248: 
        !           249: /* -----------------------------------------------------------------------
        !           250: ** FUNCTION: PR_GetCounterNameFromHandle() -- Retreive a
        !           251: ** counter's name, given its handle.
        !           252: ** 
        !           253: ** DESCRIPTION: PR_GetCounterNameFromHandle() retreives a
        !           254: ** counter's name given its handle.
        !           255: ** 
        !           256: ** INPUTS:
        !           257: **  qName: Where to store a pointer to qName.
        !           258: **  rName: Where to store a pointer to rName.
        !           259: **  description: Where to store a pointer to description.
        !           260: ** 
        !           261: ** OUTPUTS: Pointers to the Counter Feature's copies of the names
        !           262: ** used when the counters were created.
        !           263: ** 
        !           264: ** RETURNS: void
        !           265: ** 
        !           266: ** RESTRICTIONS:
        !           267: ** 
        !           268: */
        !           269: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           270: #define PR_GET_COUNTER_NAME_FROM_HANDLE(handle,qName,rName,description)\
        !           271:     PR_GetCounterNameFromHandle((handle),(qName),(rName),(description))
        !           272: #else
        !           273: #define PR_GET_COUNTER_NAME_FROM_HANDLE(handle,qName,rName,description )
        !           274: #endif
        !           275: 
        !           276: NSPR_API(void) 
        !           277:    PR_GetCounterNameFromHandle( 
        !           278:        PRCounterHandle handle,  
        !           279:        const char **qName, 
        !           280:        const char **rName, 
        !           281:        const char **description 
        !           282: );
        !           283: 
        !           284: 
        !           285: /* -----------------------------------------------------------------------
        !           286: ** FUNCTION: PR_IncrementCounter() -- Add one to the referenced
        !           287: ** counter.
        !           288: ** 
        !           289: ** DESCRIPTION: Add one to the referenced counter.
        !           290: ** 
        !           291: ** INPUTS:
        !           292: **  handle: The PRCounterHandle of the counter to be incremented
        !           293: ** 
        !           294: ** OUTPUTS: The counter is incrementd.
        !           295: ** 
        !           296: ** RETURNS: void
        !           297: ** 
        !           298: ** RESTRICTIONS:
        !           299: ** 
        !           300: */
        !           301: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           302: #define PR_INCREMENT_COUNTER(handle) PR_IncrementCounter(handle)
        !           303: #else
        !           304: #define PR_INCREMENT_COUNTER(handle)
        !           305: #endif
        !           306: 
        !           307: NSPR_API(void) 
        !           308:    PR_IncrementCounter( 
        !           309:        PRCounterHandle handle
        !           310: );
        !           311: 
        !           312: 
        !           313: /* -----------------------------------------------------------------------
        !           314: ** FUNCTION: PR_DecrementCounter() -- Subtract one from the
        !           315: ** referenced counter
        !           316: ** 
        !           317: ** DESCRIPTION: Subtract one from the referenced counter.
        !           318: ** 
        !           319: ** INPUTS: 
        !           320: **  handle: The PRCounterHandle of the coutner to be
        !           321: ** decremented.
        !           322: ** 
        !           323: ** OUTPUTS: the counter is decremented.
        !           324: ** 
        !           325: ** RETURNS: void
        !           326: ** 
        !           327: ** RESTRICTIONS:
        !           328: ** 
        !           329: */
        !           330: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           331: #define PR_DECREMENT_COUNTER(handle) PR_DecrementCounter(handle)
        !           332: #else
        !           333: #define PR_DECREMENT_COUNTER(handle)
        !           334: #endif
        !           335: 
        !           336: NSPR_API(void) 
        !           337:    PR_DecrementCounter( 
        !           338:        PRCounterHandle handle
        !           339: );
        !           340: 
        !           341: /* -----------------------------------------------------------------------
        !           342: ** FUNCTION: PR_AddToCounter() -- Add a value to a counter.
        !           343: ** 
        !           344: ** DESCRIPTION: Add value to the counter referenced by handle.
        !           345: ** 
        !           346: ** INPUTS:
        !           347: **  handle: the PRCounterHandle of the counter to be added to.
        !           348: ** 
        !           349: **  value: the value to be added to the counter.
        !           350: ** 
        !           351: ** OUTPUTS: new value for counter.
        !           352: ** 
        !           353: ** RETURNS: void
        !           354: ** 
        !           355: ** RESTRICTIONS:
        !           356: ** 
        !           357: */
        !           358: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           359: #define PR_ADD_TO_COUNTER(handle,value)\
        !           360:     PR_AddToCounter((handle),(value))
        !           361: #else
        !           362: #define PR_ADD_TO_COUNTER(handle,value)
        !           363: #endif
        !           364: 
        !           365: NSPR_API(void) 
        !           366:    PR_AddToCounter( 
        !           367:        PRCounterHandle handle, 
        !           368:        PRUint32 value 
        !           369: );
        !           370: 
        !           371: 
        !           372: /* -----------------------------------------------------------------------
        !           373: ** FUNCTION: PR_SubtractFromCounter() -- A value is subtracted
        !           374: ** from a counter.
        !           375: ** 
        !           376: ** DESCRIPTION:
        !           377: ** Subtract a value from a counter.
        !           378: ** 
        !           379: ** INPUTS:
        !           380: **  handle: the PRCounterHandle of the counter to be subtracted
        !           381: ** from.
        !           382: ** 
        !           383: **  value: the value to be subtracted from the counter.
        !           384: ** 
        !           385: ** OUTPUTS: new value for counter
        !           386: ** 
        !           387: ** RETURNS: void
        !           388: ** 
        !           389: ** RESTRICTIONS:
        !           390: ** 
        !           391: */
        !           392: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           393: #define PR_SUBTRACT_FROM_COUNTER(handle,value)\
        !           394:     PR_SubtractFromCounter((handle),(value))
        !           395: #else
        !           396: #define PR_SUBTRACT_FROM_COUNTER(handle,value)
        !           397: #endif
        !           398: 
        !           399: NSPR_API(void) 
        !           400:    PR_SubtractFromCounter( 
        !           401:        PRCounterHandle handle, 
        !           402:        PRUint32 value 
        !           403: );
        !           404: 
        !           405: 
        !           406: /* -----------------------------------------------------------------------
        !           407: ** FUNCTION: PR_GetCounter() -- Retreive the value of a counter
        !           408: ** 
        !           409: ** DESCRIPTION:
        !           410: ** Retreive the value of a counter.
        !           411: ** 
        !           412: ** INPUTS:
        !           413: **  handle: the PR_CounterHandle of the counter to be retreived
        !           414: ** 
        !           415: ** OUTPUTS:
        !           416: ** 
        !           417: ** RETURNS: The value of the referenced counter
        !           418: ** 
        !           419: ** RESTRICTIONS:
        !           420: ** 
        !           421: */
        !           422: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           423: #define PR_GET_COUNTER(counter,handle)\
        !           424:     (counter) = PR_GetCounter((handle))
        !           425: #else
        !           426: #define PR_GET_COUNTER(counter,handle) 0
        !           427: #endif
        !           428: 
        !           429: NSPR_API(PRUint32) 
        !           430:    PR_GetCounter( 
        !           431:        PRCounterHandle handle 
        !           432: );
        !           433: 
        !           434: /* -----------------------------------------------------------------------
        !           435: ** FUNCTION: PR_SetCounter() -- Replace the content of counter
        !           436: ** with value.
        !           437: ** 
        !           438: ** DESCRIPTION: The contents of the referenced counter are
        !           439: ** replaced by value.
        !           440: ** 
        !           441: ** INPUTS:
        !           442: **  handle: the PRCounterHandle of the counter whose contents
        !           443: ** are to be replaced.
        !           444: ** 
        !           445: **  value: the new value of the counter.
        !           446: ** 
        !           447: ** OUTPUTS:
        !           448: ** 
        !           449: ** RETURNS: void
        !           450: ** 
        !           451: ** RESTRICTIONS:
        !           452: ** 
        !           453: */
        !           454: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           455: #define PR_SET_COUNTER(handle,value) PR_SetCounter((handle),(value))
        !           456: #else
        !           457: #define PR_SET_COUNTER(handle,value)
        !           458: #endif
        !           459: 
        !           460: NSPR_API(void) 
        !           461:    PR_SetCounter( 
        !           462:        PRCounterHandle handle, 
        !           463:        PRUint32 value 
        !           464: );
        !           465: 
        !           466: 
        !           467: /* -----------------------------------------------------------------------
        !           468: ** FUNCTION: PR_FindNextCounterQname() -- Retreive the next QName counter
        !           469: ** handle iterator
        !           470: ** 
        !           471: ** DESCRIPTION:
        !           472: ** PR_FindNextCounterQname() retreives the first or next Qname
        !           473: ** the counter data base, depending on the value of handle. When
        !           474: ** handle is NULL, the function attempts to retreive the first
        !           475: ** QName handle in the database. When handle is a handle previosly
        !           476: ** retreived QName handle, then the function attempts to retreive
        !           477: ** the next QName handle.
        !           478: ** 
        !           479: ** INPUTS: 
        !           480: **  handle: PRCounterHandle or NULL.
        !           481: ** 
        !           482: ** OUTPUTS: returned
        !           483: ** 
        !           484: ** RETURNS: PRCounterHandle or NULL when no more QName counter
        !           485: ** handles are present.
        !           486: ** 
        !           487: ** RESTRICTIONS:
        !           488: **  A concurrent PR_CreateCounter() or PR_DestroyCounter() may
        !           489: ** cause unpredictable results.
        !           490: ** 
        !           491: ** A PRCounterHandle returned from this function may only be used
        !           492: ** in another PR_FindNextCounterQname() function call; other
        !           493: ** operations may cause unpredictable results.
        !           494: ** 
        !           495: */
        !           496: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           497: #define PR_FIND_NEXT_COUNTER_QNAME(next,handle)\
        !           498:     (next) = PR_FindNextCounterQname((handle))
        !           499: #else
        !           500: #define PR_FIND_NEXT_COUNTER_QNAME(next,handle) NULL
        !           501: #endif
        !           502: 
        !           503: NSPR_API(PRCounterHandle) 
        !           504:    PR_FindNextCounterQname( 
        !           505:         PRCounterHandle handle
        !           506: );
        !           507: 
        !           508: /* -----------------------------------------------------------------------
        !           509: ** FUNCTION: PR_FindNextCounterRname() -- Retreive the next RName counter
        !           510: ** handle iterator
        !           511: ** 
        !           512: ** DESCRIPTION:
        !           513: ** PR_FindNextCounterRname() retreives the first or next RNname
        !           514: ** handle from the counter data base, depending on the
        !           515: ** value of handle. When handle is NULL, the function attempts to
        !           516: ** retreive the first RName handle in the database. When handle is
        !           517: ** a handle previosly retreived RName handle, then the function
        !           518: ** attempts to retreive the next RName handle.
        !           519: ** 
        !           520: ** INPUTS:
        !           521: **  handle: PRCounterHandle or NULL.
        !           522: **  qhandle: PRCounterHandle of a previously aquired via
        !           523: ** PR_FIND_NEXT_QNAME_HANDLE()
        !           524: ** 
        !           525: ** OUTPUTS: returned
        !           526: ** 
        !           527: ** RETURNS: PRCounterHandle or NULL when no more RName counter
        !           528: ** handles are present.
        !           529: ** 
        !           530: ** RESTRICTIONS:
        !           531: **  A concurrent PR_CreateCounter() or PR_DestroyCounter() may
        !           532: ** cause unpredictable results.
        !           533: ** 
        !           534: ** A PRCounterHandle returned from this function may only be used
        !           535: ** in another PR_FindNextCounterRname() function call; other
        !           536: ** operations may cause unpredictable results.
        !           537: ** 
        !           538: */
        !           539: #if defined(DEBUG) || defined(FORCE_NSPR_COUNTERS)
        !           540: #define PR_FIND_NEXT_COUNTER_RNAME(next,rhandle,qhandle)\
        !           541:     (next) = PR_FindNextCounterRname((rhandle),(qhandle))
        !           542: #else
        !           543: #define PR_FIND_NEXT_COUNTER_RNAME(next,rhandle,qhandle)
        !           544: #endif
        !           545: 
        !           546: NSPR_API(PRCounterHandle) 
        !           547:    PR_FindNextCounterRname( 
        !           548:         PRCounterHandle rhandle,
        !           549:         PRCounterHandle qhandle
        !           550: );
        !           551: 
        !           552: PR_END_EXTERN_C
        !           553: 
        !           554: #endif /* prcountr_h___ */

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