RetroZilla/xpcom/ds/nsStaticNameTable.cpp

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of the GNU General Public License Version 2 or later (the "GPL"),
* or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
/* Class to manage lookup of static names in a table. */
#include "nsCRT.h"
#include "nscore.h"
#include "nsString.h"
#include "nsReadableUtils.h"
#define PL_ARENA_CONST_ALIGN_MASK 3
#include "nsStaticNameTable.h"
struct NameTableEntry : public PLDHashEntryHdr
{
// no ownership here!
const char *mKey;
PRInt32 mIndex;
};
PR_STATIC_CALLBACK(PRBool)
matchNameKeysCaseInsensitive(PLDHashTable*, const PLDHashEntryHdr* aHdr,
const void* key)
{
const NameTableEntry* entry =
NS_STATIC_CAST(const NameTableEntry *, aHdr);
const char *keyValue = NS_STATIC_CAST(const char*, key);
return (nsCRT::strcasecmp(entry->mKey, keyValue)==0);
}
/*
* caseInsensitiveHashKey is just like PL_DHashStringKey except it
* uses (*s & ~0x20) instead of simply *s. This means that "aFOO" and
* "afoo" and "aFoo" will all hash to the same thing. It also means
* that some strings that aren't case-insensensitively equal will hash
* to the same value, but it's just a hash function so it doesn't
* matter.
*/
PR_STATIC_CALLBACK(PLDHashNumber)
caseInsensitiveStringHashKey(PLDHashTable *table, const void *key)
{
PLDHashNumber h = 0;
for (const unsigned char* s =
NS_STATIC_CAST(const unsigned char*, key);
*s != '\0';
s++)
h = (h >> (PL_DHASH_BITS - 4)) ^ (h << 4) ^ (*s & ~0x20);
return h;
}
static const struct PLDHashTableOps nametable_CaseInsensitiveHashTableOps = {
PL_DHashAllocTable,
PL_DHashFreeTable,
PL_DHashGetKeyStub,
caseInsensitiveStringHashKey,
matchNameKeysCaseInsensitive,
PL_DHashMoveEntryStub,
PL_DHashClearEntryStub,
PL_DHashFinalizeStub,
nsnull,
};
nsStaticCaseInsensitiveNameTable::nsStaticCaseInsensitiveNameTable()
: mNameArray(nsnull), mNullStr("")
{
MOZ_COUNT_CTOR(nsStaticCaseInsensitiveNameTable);
mNameTable.ops = nsnull;
}
nsStaticCaseInsensitiveNameTable::~nsStaticCaseInsensitiveNameTable()
{
if (mNameArray) {
// manually call the destructor on placement-new'ed objects
for (PRUint32 index = 0; index < mNameTable.entryCount; index++) {
mNameArray[index].~nsDependentCString();
}
nsMemory::Free((void*)mNameArray);
}
if (mNameTable.ops)
PL_DHashTableFinish(&mNameTable);
MOZ_COUNT_DTOR(nsStaticCaseInsensitiveNameTable);
}
PRBool
nsStaticCaseInsensitiveNameTable::Init(const char* const aNames[], PRInt32 Count)
{
NS_ASSERTION(!mNameArray, "double Init");
NS_ASSERTION(!mNameTable.ops, "double Init");
NS_ASSERTION(aNames, "null name table");
NS_ASSERTION(Count, "0 count");
mNameArray = (nsDependentCString*)
nsMemory::Alloc(Count * sizeof(nsDependentCString));
if (!mNameArray)
return PR_FALSE;
if (!PL_DHashTableInit(&mNameTable,
&nametable_CaseInsensitiveHashTableOps,
nsnull, sizeof(NameTableEntry), Count)) {
mNameTable.ops = nsnull;
return PR_FALSE;
}
for (PRInt32 index = 0; index < Count; ++index) {
const char* raw = aNames[index];
#ifdef DEBUG
{
// verify invariants of contents
nsCAutoString temp1(raw);
nsDependentCString temp2(raw);
ToLowerCase(temp1);
NS_ASSERTION(temp1.Equals(temp2), "upper case char in table");
NS_ASSERTION(nsCRT::IsAscii(raw),
"non-ascii string in table -- "
"case-insensitive matching won't work right");
}
#endif
// use placement-new to initialize the string object
new (&mNameArray[index]) nsDependentCString(raw);
NameTableEntry *entry =
NS_STATIC_CAST(NameTableEntry*,
PL_DHashTableOperate(&mNameTable, raw, PL_DHASH_ADD));
if (!entry) continue;
NS_ASSERTION(entry->mKey == 0, "Entry already exists!");
entry->mKey = raw; // not owned!
entry->mIndex = index;
}
return PR_TRUE;
}
inline PRInt32
LookupFlatKeyword(const nsAFlatCString& aKeyword,
PLDHashTable& aTable)
{
NameTableEntry *entry =
NS_STATIC_CAST(NameTableEntry*,
PL_DHashTableOperate(&aTable, aKeyword.get(), PL_DHASH_LOOKUP));
if (PL_DHASH_ENTRY_IS_FREE(entry))
return nsStaticCaseInsensitiveNameTable::NOT_FOUND;
return entry->mIndex;
}
PRInt32
nsStaticCaseInsensitiveNameTable::Lookup(const nsACString& aName)
{
NS_ASSERTION(mNameArray, "not inited");
NS_ASSERTION(mNameTable.ops, "not inited");
return LookupFlatKeyword(PromiseFlatCString(aName), mNameTable);
}
PRInt32
nsStaticCaseInsensitiveNameTable::Lookup(const nsAString& aName)
{
NS_ASSERTION(mNameArray, "not inited");
NS_ASSERTION(mNameTable.ops, "not inited");
nsCAutoString cstring;
cstring.AssignWithConversion(aName);
return LookupFlatKeyword(cstring, mNameTable);
}
const nsAFlatCString&
nsStaticCaseInsensitiveNameTable::GetStringValue(PRInt32 index)
{
NS_ASSERTION(mNameArray, "not inited");
NS_ASSERTION(mNameTable.ops, "not inited");
if ((NOT_FOUND < index) && ((PRUint32)index < mNameTable.entryCount)) {
return mNameArray[index];
}
return mNullStr;
}