/* * tclLiteral.c -- * * Implementation of the global and ByteCode-local literal tables * used to manage the Tcl objects created for literal values during * compilation of Tcl scripts. This implementation borrows heavily * from the more general hashtable implementation of Tcl hash tables * that appears in tclHash.c. * * Copyright (c) 1997-1998 Sun Microsystems, Inc. * * See the file "license.terms" for information on usage and redistribution * of this file, and for a DISCLAIMER OF ALL WARRANTIES. * * RCS: @(#) $Id: tclLiteral.c,v 1.1.1.1 2007/07/10 15:04:23 duncan Exp $ */ #include "tclInt.h" #include "tclCompile.h" #include "tclPort.h" /* * When there are this many entries per bucket, on average, rebuild * a literal's hash table to make it larger. */ #define REBUILD_MULTIPLIER 3 /* * Procedure prototypes for static procedures in this file: */ static int AddLocalLiteralEntry _ANSI_ARGS_(( CompileEnv *envPtr, LiteralEntry *globalPtr, int localHash)); static void ExpandLocalLiteralArray _ANSI_ARGS_(( CompileEnv *envPtr)); static unsigned int HashString _ANSI_ARGS_((CONST char *bytes, int length)); static void RebuildLiteralTable _ANSI_ARGS_(( LiteralTable *tablePtr)); /* *---------------------------------------------------------------------- * * TclInitLiteralTable -- * * This procedure is called to initialize the fields of a literal table * structure for either an interpreter or a compilation's CompileEnv * structure. * * Results: * None. * * Side effects: * The literal table is made ready for use. * *---------------------------------------------------------------------- */ void TclInitLiteralTable(tablePtr) register LiteralTable *tablePtr; /* Pointer to table structure, which * is supplied by the caller. */ { #if (TCL_SMALL_HASH_TABLE != 4) panic("TclInitLiteralTable: TCL_SMALL_HASH_TABLE is %d, not 4\n", TCL_SMALL_HASH_TABLE); #endif tablePtr->buckets = tablePtr->staticBuckets; tablePtr->staticBuckets[0] = tablePtr->staticBuckets[1] = 0; tablePtr->staticBuckets[2] = tablePtr->staticBuckets[3] = 0; tablePtr->numBuckets = TCL_SMALL_HASH_TABLE; tablePtr->numEntries = 0; tablePtr->rebuildSize = TCL_SMALL_HASH_TABLE*REBUILD_MULTIPLIER; tablePtr->mask = 3; } /* *---------------------------------------------------------------------- * * TclDeleteLiteralTable -- * * This procedure frees up everything associated with a literal table * except for the table's structure itself. * * Results: * None. * * Side effects: * Each literal in the table is released: i.e., its reference count * in the global literal table is decremented and, if it becomes zero, * the literal is freed. In addition, the table's bucket array is * freed. * *---------------------------------------------------------------------- */ void TclDeleteLiteralTable(interp, tablePtr) Tcl_Interp *interp; /* Interpreter containing shared literals * referenced by the table to delete. */ LiteralTable *tablePtr; /* Points to the literal table to delete. */ { LiteralEntry *entryPtr; int i, start; /* * Release remaining literals in the table. Note that releasing a * literal might release other literals, modifying the table, so we * restart the search from the bucket chain we last found an entry. */ #ifdef TCL_COMPILE_DEBUG TclVerifyGlobalLiteralTable((Interp *) interp); #endif /*TCL_COMPILE_DEBUG*/ start = 0; while (tablePtr->numEntries > 0) { for (i = start; i < tablePtr->numBuckets; i++) { entryPtr = tablePtr->buckets[i]; if (entryPtr != NULL) { TclReleaseLiteral(interp, entryPtr->objPtr); start = i; break; } } } /* * Free up the table's bucket array if it was dynamically allocated. */ if (tablePtr->buckets != tablePtr->staticBuckets) { ckfree((char *) tablePtr->buckets); } } /* *---------------------------------------------------------------------- * * TclRegisterLiteral -- * * Find, or if necessary create, an object in a CompileEnv literal * array that has a string representation matching the argument string. * * Results: * The index in the CompileEnv's literal array that references a * shared literal matching the string. The object is created if * necessary. * * Side effects: * To maximize sharing, we look up the string in the interpreter's * global literal table. If not found, we create a new shared literal * in the global table. We then add a reference to the shared * literal in the CompileEnv's literal array. * * If onHeap is 1, this procedure is given ownership of the string: if * an object is created then its string representation is set directly * from string, otherwise the string is freed. Typically, a caller sets * onHeap 1 if "string" is an already heap-allocated buffer holding the * result of backslash substitutions. * *---------------------------------------------------------------------- */ int TclRegisterLiteral(envPtr, bytes, length, onHeap) CompileEnv *envPtr; /* Points to the CompileEnv in whose object * array an object is found or created. */ register char *bytes; /* Points to string for which to find or * create an object in CompileEnv's object * array. */ int length; /* Number of bytes in the string. If < 0, * the string consists of all bytes up to * the first null character. */ int onHeap; /* If 1 then the caller already malloc'd * bytes and ownership is passed to this * procedure. */ { Interp *iPtr = envPtr->iPtr; LiteralTable *globalTablePtr = &(iPtr->literalTable); LiteralTable *localTablePtr = &(envPtr->localLitTable); register LiteralEntry *globalPtr, *localPtr; register Tcl_Obj *objPtr; unsigned int hash; int localHash, globalHash, objIndex; long n; char buf[TCL_INTEGER_SPACE]; if (length < 0) { length = (bytes? strlen(bytes) : 0); } hash = HashString(bytes, length); /* * Is the literal already in the CompileEnv's local literal array? * If so, just return its index. */ localHash = (hash & localTablePtr->mask); for (localPtr = localTablePtr->buckets[localHash]; localPtr != NULL; localPtr = localPtr->nextPtr) { objPtr = localPtr->objPtr; if ((objPtr->length == length) && ((length == 0) || ((objPtr->bytes[0] == bytes[0]) && (memcmp(objPtr->bytes, bytes, (unsigned) length) == 0)))) { if (onHeap) { ckfree(bytes); } objIndex = (localPtr - envPtr->literalArrayPtr); #ifdef TCL_COMPILE_DEBUG TclVerifyLocalLiteralTable(envPtr); #endif /*TCL_COMPILE_DEBUG*/ return objIndex; } } /* * The literal is new to this CompileEnv. Is it in the interpreter's * global literal table? */ globalHash = (hash & globalTablePtr->mask); for (globalPtr = globalTablePtr->buckets[globalHash]; globalPtr != NULL; globalPtr = globalPtr->nextPtr) { objPtr = globalPtr->objPtr; if ((objPtr->length == length) && ((length == 0) || ((objPtr->bytes[0] == bytes[0]) && (memcmp(objPtr->bytes, bytes, (unsigned) length) == 0)))) { /* * A global literal was found. Add an entry to the CompileEnv's * local literal array. */ if (onHeap) { ckfree(bytes); } objIndex = AddLocalLiteralEntry(envPtr, globalPtr, localHash); #ifdef TCL_COMPILE_DEBUG if (globalPtr->refCount < 1) { panic("TclRegisterLiteral: global literal \"%.*s\" had bad refCount %d", (length>60? 60 : length), bytes, globalPtr->refCount); } TclVerifyLocalLiteralTable(envPtr); #endif /*TCL_COMPILE_DEBUG*/ return objIndex; } } /* * The literal is new to the interpreter. Add it to the global literal * table then add an entry to the CompileEnv's local literal array. * Convert the object to an integer object if possible. */ TclNewObj(objPtr); Tcl_IncrRefCount(objPtr); if (onHeap) { objPtr->bytes = bytes; objPtr->length = length; } else { TclInitStringRep(objPtr, bytes, length); } if (TclLooksLikeInt(bytes, length)) { /* * From here we use the objPtr, because it is NULL terminated */ if (TclGetLong((Tcl_Interp *) NULL, objPtr->bytes, &n) == TCL_OK) { TclFormatInt(buf, n); if (strcmp(objPtr->bytes, buf) == 0) { objPtr->internalRep.longValue = n; objPtr->typePtr = &tclIntType; } } } #ifdef TCL_COMPILE_DEBUG if (TclLookupLiteralEntry((Tcl_Interp *) iPtr, objPtr) != NULL) { panic("TclRegisterLiteral: literal \"%.*s\" found globally but shouldn't be", (length>60? 60 : length), bytes); } #endif globalPtr = (LiteralEntry *) ckalloc((unsigned) sizeof(LiteralEntry)); globalPtr->objPtr = objPtr; globalPtr->refCount = 0; globalPtr->nextPtr = globalTablePtr->buckets[globalHash]; globalTablePtr->buckets[globalHash] = globalPtr; globalTablePtr->numEntries++; /* * If the global literal table has exceeded a decent size, rebuild it * with more buckets. */ if (globalTablePtr->numEntries >= globalTablePtr->rebuildSize) { RebuildLiteralTable(globalTablePtr); } objIndex = AddLocalLiteralEntry(envPtr, globalPtr, localHash); #ifdef TCL_COMPILE_DEBUG TclVerifyGlobalLiteralTable(iPtr); TclVerifyLocalLiteralTable(envPtr); { LiteralEntry *entryPtr; int found, i; found = 0; for (i = 0; i < globalTablePtr->numBuckets; i++) { for (entryPtr = globalTablePtr->buckets[i]; entryPtr != NULL; entryPtr = entryPtr->nextPtr) { if ((entryPtr == globalPtr) && (entryPtr->objPtr == objPtr)) { found = 1; } } } if (!found) { panic("TclRegisterLiteral: literal \"%.*s\" wasn't global", (length>60? 60 : length), bytes); } } #endif /*TCL_COMPILE_DEBUG*/ #ifdef TCL_COMPILE_STATS iPtr->stats.numLiteralsCreated++; iPtr->stats.totalLitStringBytes += (double) (length + 1); iPtr->stats.currentLitStringBytes += (double) (length + 1); iPtr->stats.literalCount[TclLog2(length)]++; #endif /*TCL_COMPILE_STATS*/ return objIndex; } /* *---------------------------------------------------------------------- * * TclLookupLiteralEntry -- * * Finds the LiteralEntry that corresponds to a literal Tcl object * holding a literal. * * Results: * Returns the matching LiteralEntry if found, otherwise NULL. * * Side effects: * None. * *---------------------------------------------------------------------- */ LiteralEntry * TclLookupLiteralEntry(interp, objPtr) Tcl_Interp *interp; /* Interpreter for which objPtr was created * to hold a literal. */ register Tcl_Obj *objPtr; /* Points to a Tcl object holding a * literal that was previously created by a * call to TclRegisterLiteral. */ { Interp *iPtr = (Interp *) interp; LiteralTable *globalTablePtr = &(iPtr->literalTable); register LiteralEntry *entryPtr; char *bytes; int length, globalHash; bytes = Tcl_GetStringFromObj(objPtr, &length); globalHash = (HashString(bytes, length) & globalTablePtr->mask); for (entryPtr = globalTablePtr->buckets[globalHash]; entryPtr != NULL; entryPtr = entryPtr->nextPtr) { if (entryPtr->objPtr == objPtr) { return entryPtr; } } return NULL; } /* *---------------------------------------------------------------------- * * TclHideLiteral -- * * Remove a literal entry from the literal hash tables, leaving it in * the literal array so existing references continue to function. * This makes it possible to turn a shared literal into a private * literal that cannot be shared. * * Results: * None. * * Side effects: * Removes the literal from the local hash table and decrements the * global hash entry's reference count. * *---------------------------------------------------------------------- */ void TclHideLiteral(interp, envPtr, index) Tcl_Interp *interp; /* Interpreter for which objPtr was created * to hold a literal. */ register CompileEnv *envPtr; /* Points to CompileEnv whose literal array * contains the entry being hidden. */ int index; /* The index of the entry in the literal * array. */ { LiteralEntry **nextPtrPtr, *entryPtr, *lPtr; LiteralTable *localTablePtr = &(envPtr->localLitTable); int localHash, length; char *bytes; Tcl_Obj *newObjPtr; lPtr = &(envPtr->literalArrayPtr[index]); /* * To avoid unwanted sharing we need to copy the object and remove it from * the local and global literal tables. It still has a slot in the literal * array so it can be referred to by byte codes, but it will not be matched * by literal searches. */ newObjPtr = Tcl_DuplicateObj(lPtr->objPtr); Tcl_IncrRefCount(newObjPtr); TclReleaseLiteral(interp, lPtr->objPtr); lPtr->objPtr = newObjPtr; bytes = Tcl_GetStringFromObj(newObjPtr, &length); localHash = (HashString(bytes, length) & localTablePtr->mask); nextPtrPtr = &localTablePtr->buckets[localHash]; for (entryPtr = *nextPtrPtr; entryPtr != NULL; entryPtr = *nextPtrPtr) { if (entryPtr == lPtr) { *nextPtrPtr = lPtr->nextPtr; lPtr->nextPtr = NULL; localTablePtr->numEntries--; break; } nextPtrPtr = &entryPtr->nextPtr; } } /* *---------------------------------------------------------------------- * * TclAddLiteralObj -- * * Add a single literal object to the literal array. This * function does not add the literal to the local or global * literal tables. The caller is expected to add the entry * to whatever tables are appropriate. * * Results: * The index in the CompileEnv's literal array that references the * literal. Stores the pointer to the new literal entry in the * location referenced by the localPtrPtr argument. * * Side effects: * Expands the literal array if necessary. Increments the refcount * on the literal object. * *---------------------------------------------------------------------- */ int TclAddLiteralObj(envPtr, objPtr, litPtrPtr) register CompileEnv *envPtr; /* Points to CompileEnv in whose literal * array the object is to be inserted. */ Tcl_Obj *objPtr; /* The object to insert into the array. */ LiteralEntry **litPtrPtr; /* The location where the pointer to the * new literal entry should be stored. * May be NULL. */ { register LiteralEntry *lPtr; int objIndex; if (envPtr->literalArrayNext >= envPtr->literalArrayEnd) { ExpandLocalLiteralArray(envPtr); } objIndex = envPtr->literalArrayNext; envPtr->literalArrayNext++; lPtr = &(envPtr->literalArrayPtr[objIndex]); lPtr->objPtr = objPtr; Tcl_IncrRefCount(objPtr); lPtr->refCount = -1; /* i.e., unused */ lPtr->nextPtr = NULL; if (litPtrPtr) { *litPtrPtr = lPtr; } return objIndex; } /* *---------------------------------------------------------------------- * * AddLocalLiteralEntry -- * * Insert a new literal into a CompileEnv's local literal array. * * Results: * The index in the CompileEnv's literal array that references the * literal. * * Side effects: * Increments the ref count of the global LiteralEntry since the * CompileEnv now refers to the literal. Expands the literal array * if necessary. May rebuild the hash bucket array of the CompileEnv's * literal array if it becomes too large. * *---------------------------------------------------------------------- */ static int AddLocalLiteralEntry(envPtr, globalPtr, localHash) register CompileEnv *envPtr; /* Points to CompileEnv in whose literal * array the object is to be inserted. */ LiteralEntry *globalPtr; /* Points to the global LiteralEntry for * the literal to add to the CompileEnv. */ int localHash; /* Hash value for the literal's string. */ { register LiteralTable *localTablePtr = &(envPtr->localLitTable); LiteralEntry *localPtr; int objIndex; objIndex = TclAddLiteralObj(envPtr, globalPtr->objPtr, &localPtr); /* * Add the literal to the local table. */ localPtr->nextPtr = localTablePtr->buckets[localHash]; localTablePtr->buckets[localHash] = localPtr; localTablePtr->numEntries++; globalPtr->refCount++; /* * If the CompileEnv's local literal table has exceeded a decent size, * rebuild it with more buckets. */ if (localTablePtr->numEntries >= localTablePtr->rebuildSize) { RebuildLiteralTable(localTablePtr); } #ifdef TCL_COMPILE_DEBUG TclVerifyLocalLiteralTable(envPtr); { char *bytes; int length, found, i; found = 0; for (i = 0; i < localTablePtr->numBuckets; i++) { for (localPtr = localTablePtr->buckets[i]; localPtr != NULL; localPtr = localPtr->nextPtr) { if (localPtr->objPtr == globalPtr->objPtr) { found = 1; } } } if (!found) { bytes = Tcl_GetStringFromObj(globalPtr->objPtr, &length); panic("AddLocalLiteralEntry: literal \"%.*s\" wasn't found locally", (length>60? 60 : length), bytes); } } #endif /*TCL_COMPILE_DEBUG*/ return objIndex; } /* *---------------------------------------------------------------------- * * ExpandLocalLiteralArray -- * * Procedure that uses malloc to allocate more storage for a * CompileEnv's local literal array. * * Results: * None. * * Side effects: * The literal array in *envPtr is reallocated to a new array of * double the size, and if envPtr->mallocedLiteralArray is non-zero * the old array is freed. Entries are copied from the old array * to the new one. The local literal table is updated to refer to * the new entries. * *---------------------------------------------------------------------- */ static void ExpandLocalLiteralArray(envPtr) register CompileEnv *envPtr; /* Points to the CompileEnv whose object * array must be enlarged. */ { /* * The current allocated local literal entries are stored between * elements 0 and (envPtr->literalArrayNext - 1) [inclusive]. */ LiteralTable *localTablePtr = &(envPtr->localLitTable); int currElems = envPtr->literalArrayNext; size_t currBytes = (currElems * sizeof(LiteralEntry)); register LiteralEntry *currArrayPtr = envPtr->literalArrayPtr; register LiteralEntry *newArrayPtr = (LiteralEntry *) ckalloc((unsigned) (2 * currBytes)); int i; /* * Copy from the old literal array to the new, then update the local * literal table's bucket array. */ memcpy((VOID *) newArrayPtr, (VOID *) currArrayPtr, currBytes); for (i = 0; i < currElems; i++) { if (currArrayPtr[i].nextPtr == NULL) { newArrayPtr[i].nextPtr = NULL; } else { newArrayPtr[i].nextPtr = newArrayPtr + (currArrayPtr[i].nextPtr - currArrayPtr); } } for (i = 0; i < localTablePtr->numBuckets; i++) { if (localTablePtr->buckets[i] != NULL) { localTablePtr->buckets[i] = newArrayPtr + (localTablePtr->buckets[i] - currArrayPtr); } } /* * Free the old literal array if needed, and mark the new literal * array as malloced. */ if (envPtr->mallocedLiteralArray) { ckfree((char *) currArrayPtr); } envPtr->literalArrayPtr = newArrayPtr; envPtr->literalArrayEnd = (2 * currElems); envPtr->mallocedLiteralArray = 1; } /* *---------------------------------------------------------------------- * * TclReleaseLiteral -- * * This procedure releases a reference to one of the shared Tcl objects * that hold literals. It is called to release the literals referenced * by a ByteCode that is being destroyed, and it is also called by * TclDeleteLiteralTable. * * Results: * None. * * Side effects: * The reference count for the global LiteralTable entry that * corresponds to the literal is decremented. If no other reference * to a global literal object remains, it is freed. * *---------------------------------------------------------------------- */ void TclReleaseLiteral(interp, objPtr) Tcl_Interp *interp; /* Interpreter for which objPtr was created * to hold a literal. */ register Tcl_Obj *objPtr; /* Points to a literal object that was * previously created by a call to * TclRegisterLiteral. */ { Interp *iPtr = (Interp *) interp; LiteralTable *globalTablePtr = &(iPtr->literalTable); register LiteralEntry *entryPtr, *prevPtr; ByteCode* codePtr; char *bytes; int length, index; bytes = Tcl_GetStringFromObj(objPtr, &length); index = (HashString(bytes, length) & globalTablePtr->mask); /* * Check to see if the object is in the global literal table and * remove this reference. The object may not be in the table if * it is a hidden local literal. */ for (prevPtr = NULL, entryPtr = globalTablePtr->buckets[index]; entryPtr != NULL; prevPtr = entryPtr, entryPtr = entryPtr->nextPtr) { if (entryPtr->objPtr == objPtr) { entryPtr->refCount--; /* * If the literal is no longer being used by any ByteCode, * delete the entry then remove the reference corresponding * to the global literal table entry (decrement the ref count * of the object). */ if (entryPtr->refCount == 0) { if (prevPtr == NULL) { globalTablePtr->buckets[index] = entryPtr->nextPtr; } else { prevPtr->nextPtr = entryPtr->nextPtr; } ckfree((char *) entryPtr); globalTablePtr->numEntries--; TclDecrRefCount(objPtr); /* * Check if the LiteralEntry is only being kept alive by * a circular reference from a ByteCode stored as its * internal rep. In that case, set the ByteCode object array * entry NULL to signal to TclCleanupByteCode to not try to * release this about to be freed literal again. */ if (objPtr->typePtr == &tclByteCodeType) { codePtr = (ByteCode *) objPtr->internalRep.otherValuePtr; if ((codePtr->numLitObjects == 1) && (codePtr->objArrayPtr[0] == objPtr)) { codePtr->objArrayPtr[0] = NULL; } } #ifdef TCL_COMPILE_STATS iPtr->stats.currentLitStringBytes -= (double) (length + 1); #endif /*TCL_COMPILE_STATS*/ } break; } } /* * Remove the reference corresponding to the local literal table * entry. */ Tcl_DecrRefCount(objPtr); } /* *---------------------------------------------------------------------- * * HashString -- * * Compute a one-word summary of a text string, which can be * used to generate a hash index. * * Results: * The return value is a one-word summary of the information in * string. * * Side effects: * None. * *---------------------------------------------------------------------- */ static unsigned int HashString(bytes, length) register CONST char *bytes; /* String for which to compute hash * value. */ int length; /* Number of bytes in the string. */ { register unsigned int result; register int i; /* * I tried a zillion different hash functions and asked many other * people for advice. Many people had their own favorite functions, * all different, but no-one had much idea why they were good ones. * I chose the one below (multiply by 9 and add new character) * because of the following reasons: * * 1. Multiplying by 10 is perfect for keys that are decimal strings, * and multiplying by 9 is just about as good. * 2. Times-9 is (shift-left-3) plus (old). This means that each * character's bits hang around in the low-order bits of the * hash value for ever, plus they spread fairly rapidly up to * the high-order bits to fill out the hash value. This seems * works well both for decimal and non-decimal strings. */ result = 0; for (i = 0; i < length; i++) { result += (result<<3) + *bytes++; } return result; } /* *---------------------------------------------------------------------- * * RebuildLiteralTable -- * * This procedure is invoked when the ratio of entries to hash buckets * becomes too large in a local or global literal table. It allocates * a larger bucket array and moves the entries into the new buckets. * * Results: * None. * * Side effects: * Memory gets reallocated and entries get rehashed into new buckets. * *---------------------------------------------------------------------- */ static void RebuildLiteralTable(tablePtr) register LiteralTable *tablePtr; /* Local or global table to enlarge. */ { LiteralEntry **oldBuckets; register LiteralEntry **oldChainPtr, **newChainPtr; register LiteralEntry *entryPtr; LiteralEntry **bucketPtr; char *bytes; int oldSize, count, index, length; oldSize = tablePtr->numBuckets; oldBuckets = tablePtr->buckets; /* * Allocate and initialize the new bucket array, and set up * hashing constants for new array size. */ tablePtr->numBuckets *= 4; tablePtr->buckets = (LiteralEntry **) ckalloc((unsigned) (tablePtr->numBuckets * sizeof(LiteralEntry *))); for (count = tablePtr->numBuckets, newChainPtr = tablePtr->buckets; count > 0; count--, newChainPtr++) { *newChainPtr = NULL; } tablePtr->rebuildSize *= 4; tablePtr->mask = (tablePtr->mask << 2) + 3; /* * Rehash all of the existing entries into the new bucket array. */ for (oldChainPtr = oldBuckets; oldSize > 0; oldSize--, oldChainPtr++) { for (entryPtr = *oldChainPtr; entryPtr != NULL; entryPtr = *oldChainPtr) { bytes = Tcl_GetStringFromObj(entryPtr->objPtr, &length); index = (HashString(bytes, length) & tablePtr->mask); *oldChainPtr = entryPtr->nextPtr; bucketPtr = &(tablePtr->buckets[index]); entryPtr->nextPtr = *bucketPtr; *bucketPtr = entryPtr; } } /* * Free up the old bucket array, if it was dynamically allocated. */ if (oldBuckets != tablePtr->staticBuckets) { ckfree((char *) oldBuckets); } } #ifdef TCL_COMPILE_STATS /* *---------------------------------------------------------------------- * * TclLiteralStats -- * * Return statistics describing the layout of the hash table * in its hash buckets. * * Results: * The return value is a malloc-ed string containing information * about tablePtr. It is the caller's responsibility to free * this string. * * Side effects: * None. * *---------------------------------------------------------------------- */ char * TclLiteralStats(tablePtr) LiteralTable *tablePtr; /* Table for which to produce stats. */ { #define NUM_COUNTERS 10 int count[NUM_COUNTERS], overflow, i, j; double average, tmp; register LiteralEntry *entryPtr; char *result, *p; /* * Compute a histogram of bucket usage. For each bucket chain i, * j is the number of entries in the chain. */ for (i = 0; i < NUM_COUNTERS; i++) { count[i] = 0; } overflow = 0; average = 0.0; for (i = 0; i < tablePtr->numBuckets; i++) { j = 0; for (entryPtr = tablePtr->buckets[i]; entryPtr != NULL; entryPtr = entryPtr->nextPtr) { j++; } if (j < NUM_COUNTERS) { count[j]++; } else { overflow++; } tmp = j; average += (tmp+1.0)*(tmp/tablePtr->numEntries)/2.0; } /* * Print out the histogram and a few other pieces of information. */ result = (char *) ckalloc((unsigned) ((NUM_COUNTERS*60) + 300)); sprintf(result, "%d entries in table, %d buckets\n", tablePtr->numEntries, tablePtr->numBuckets); p = result + strlen(result); for (i = 0; i < NUM_COUNTERS; i++) { sprintf(p, "number of buckets with %d entries: %d\n", i, count[i]); p += strlen(p); } sprintf(p, "number of buckets with %d or more entries: %d\n", NUM_COUNTERS, overflow); p += strlen(p); sprintf(p, "average search distance for entry: %.1f", average); return result; } #endif /*TCL_COMPILE_STATS*/ #ifdef TCL_COMPILE_DEBUG /* *---------------------------------------------------------------------- * * TclVerifyLocalLiteralTable -- * * Check a CompileEnv's local literal table for consistency. * * Results: * None. * * Side effects: * Panics if problems are found. * *---------------------------------------------------------------------- */ void TclVerifyLocalLiteralTable(envPtr) CompileEnv *envPtr; /* Points to CompileEnv whose literal * table is to be validated. */ { register LiteralTable *localTablePtr = &(envPtr->localLitTable); register LiteralEntry *localPtr; char *bytes; register int i; int length, count; count = 0; for (i = 0; i < localTablePtr->numBuckets; i++) { for (localPtr = localTablePtr->buckets[i]; localPtr != NULL; localPtr = localPtr->nextPtr) { count++; if (localPtr->refCount != -1) { bytes = Tcl_GetStringFromObj(localPtr->objPtr, &length); panic("TclVerifyLocalLiteralTable: local literal \"%.*s\" had bad refCount %d", (length>60? 60 : length), bytes, localPtr->refCount); } if (TclLookupLiteralEntry((Tcl_Interp *) envPtr->iPtr, localPtr->objPtr) == NULL) { bytes = Tcl_GetStringFromObj(localPtr->objPtr, &length); panic("TclVerifyLocalLiteralTable: local literal \"%.*s\" is not global", (length>60? 60 : length), bytes); } if (localPtr->objPtr->bytes == NULL) { panic("TclVerifyLocalLiteralTable: literal has NULL string rep"); } } } if (count != localTablePtr->numEntries) { panic("TclVerifyLocalLiteralTable: local literal table had %d entries, should be %d", count, localTablePtr->numEntries); } } /* *---------------------------------------------------------------------- * * TclVerifyGlobalLiteralTable -- * * Check an interpreter's global literal table literal for consistency. * * Results: * None. * * Side effects: * Panics if problems are found. * *---------------------------------------------------------------------- */ void TclVerifyGlobalLiteralTable(iPtr) Interp *iPtr; /* Points to interpreter whose global * literal table is to be validated. */ { register LiteralTable *globalTablePtr = &(iPtr->literalTable); register LiteralEntry *globalPtr; char *bytes; register int i; int length, count; count = 0; for (i = 0; i < globalTablePtr->numBuckets; i++) { for (globalPtr = globalTablePtr->buckets[i]; globalPtr != NULL; globalPtr = globalPtr->nextPtr) { count++; if (globalPtr->refCount < 1) { bytes = Tcl_GetStringFromObj(globalPtr->objPtr, &length); panic("TclVerifyGlobalLiteralTable: global literal \"%.*s\" had bad refCount %d", (length>60? 60 : length), bytes, globalPtr->refCount); } if (globalPtr->objPtr->bytes == NULL) { panic("TclVerifyGlobalLiteralTable: literal has NULL string rep"); } } } if (count != globalTablePtr->numEntries) { panic("TclVerifyGlobalLiteralTable: global literal table had %d entries, should be %d", count, globalTablePtr->numEntries); } } #endif /*TCL_COMPILE_DEBUG*/