/*
* 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 1.11 2001/10/11 22:28:01 msofer 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*/