/**

  * vim: set ts=4 sw=4 tw=99 noet :

  * =============================================================================

  * SourceMod

  * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.

  * =============================================================================

  *

  * This program is free software; you can redistribute it and/or modify it under

  * the terms of the GNU General Public License, version 3.0, as published by the

  * Free Software Foundation.

  * 

  * This program is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS

  * FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more

  * details.

  *

  * You should have received a copy of the GNU General Public License along with

  * this program.  If not, see <http://www.gnu.org/licenses/>.

  *

  * As a special exception, AlliedModders LLC gives you permission to link the

  * code of this program (as well as its derivative works) to "Half-Life 2," the

  * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software

  * by the Valve Corporation.  You must obey the GNU General Public License in

  * all respects for all other code used.  Additionally, AlliedModders LLC grants

  * this exception to all derivative works.  AlliedModders LLC defines further

  * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),

  * or <http://www.sourcemod.net/license.php>.

  *

  * Version: $Id$

  */

 #include <stdlib.h>

 #include "common_logic.h"

 #include <am-moveable.h>

 #include <am-refcounting.h>

 #include <sm_stringhashmap.h>

 #include "sm_memtable.h"

 HandleType_t htCellTrie;

 HandleType_t htSnapshot;

 enum EntryType

 {

 	EntryType_Cell,

 	EntryType_CellArray,

 	EntryType_String,

 };

 class Entry

 {

 	struct ArrayInfo

 	{

 		size_t length;

 		size_t maxbytes;

 		void *base() {

 			return this + 1;

 		}

 	};

 public:

 	Entry()

 		: control_(0)

 	{

 	}

 	Entry(ke::Moveable<Entry> other)

 	{

 		control_ = other->control_;

 		data_ = other->data_;

 		other->control_ = 0;

 	}

 	~Entry()

 	{

 		free(raw());

 	}

 	void setCell(cell_t value) {

 		setType(EntryType_Cell);

 		data_ = value;

 	}

 	void setArray(cell_t *cells, size_t length) {

 		ArrayInfo *array = ensureArray(length * sizeof(cell_t));

 		array->length = length;

 		memcpy(array->base(), cells, length * sizeof(cell_t));

 		setTypeAndPointer(EntryType_CellArray, array);

 	}

 	void setString(const char *str) {

 		size_t length = strlen(str);

 		ArrayInfo *array = ensureArray(length + 1);

 		array->length = length;

 		strcpy((char *)array->base(), str);

 		setTypeAndPointer(EntryType_String, array);

 	}

 	size_t arrayLength() const {

 		assert(isArray());

 		return raw()->length;

 	}

 	cell_t *array() const {

 		assert(isArray());

 		return reinterpret_cast<cell_t *>(raw()->base());

 	}

 	char *chars() const {

 		assert(isString());

 		return reinterpret_cast<char *>(raw()->base());

 	}

 	cell_t cell() const {

 		assert(isCell());

 		return data_;

 	}

 	bool isCell() const {

 		return type() == EntryType_Cell;

 	}

 	bool isArray() const {

 		return type() == EntryType_CellArray;

 	}

 	bool isString() const {

 		return type() == EntryType_String;

 	}

 private:

 	Entry(const Entry &other) KE_DELETE;

 	ArrayInfo *ensureArray(size_t bytes) {

 		ArrayInfo *array = raw();

 		if (array && array->maxbytes >= bytes)

 			return array;

 		array = (ArrayInfo *)realloc(array, bytes + sizeof(ArrayInfo));

 		if (!array)

 		{

 			fprintf(stderr, "Out of memory!\n");

 			abort();

 		}

 		array->maxbytes = bytes;

 		return array;

 	}

 	// Pointer and type are overlaid, so we have some accessors.

 	ArrayInfo *raw() const {

 		return reinterpret_cast<ArrayInfo *>(control_ & ~uintptr_t(0x3));

 	}

 	void setType(EntryType aType) {

 		control_ = uintptr_t(raw()) | uintptr_t(aType);

 		assert(type() == aType);

 	}

 	void setTypeAndPointer(EntryType aType, ArrayInfo *ptr) {

 		// malloc() should guarantee 8-byte alignment at worst

 		assert((uintptr_t(ptr) & 0x3) == 0);

 		control_ = uintptr_t(ptr) | uintptr_t(aType);

 		assert(type() == aType);

 	}

 	EntryType type() const {

 		return (EntryType)(control_ & 0x3);

 	}

 private:

 	// Contains the bits for the type, and an array pointer, if one is set.

 	uintptr_t control_;

 	// Contains data for cell-only entries.

 	cell_t data_;

 };

 struct CellTrie : public ke::Refcounted<CellTrie>

 {

 	StringHashMap<Entry> map;

 };

 struct TrieSnapshot

 {

 	TrieSnapshot()

 		: strings(128)

 	{ }

 	size_t mem_usage()

 	{

 		return length * sizeof(int) + strings.GetMemTable()->GetMemUsage();

 	}

 	size_t length;

 	ke::AutoArray<int> keys;

 	BaseStringTable strings;

 };

 class TrieHelpers : 

 	public SMGlobalClass,

 	public IHandleTypeDispatch

 {

 public: //SMGlobalClass

 	void OnSourceModAllInitialized()

 	{

 		htCellTrie = handlesys->CreateType("Trie", this, 0, NULL, NULL, g_pCoreIdent, NULL);

 		htSnapshot = handlesys->CreateType("TrieSnapshot", this, 0, NULL, NULL, g_pCoreIdent, NULL);

 	}

 	void OnSourceModShutdown()

 	{

 		handlesys->RemoveType(htSnapshot, g_pCoreIdent);

 		handlesys->RemoveType(htCellTrie, g_pCoreIdent);

 	}

 public: //IHandleTypeDispatch

 	void OnHandleDestroy(HandleType_t type, void *object)

 	{

 		if (type == htCellTrie)

 		{

 			CellTrie *pTrie = (CellTrie *)object;

 			pTrie->Release();

 		} else {

 			TrieSnapshot *snapshot = (TrieSnapshot *)object;

 			delete snapshot;

 		}

 	}

 	bool GetHandleApproxSize(HandleType_t type, void *object, unsigned int *pSize)

 	{

 		if (type == htCellTrie)

 		{

 			CellTrie *pArray = (CellTrie *)object;

 			*pSize = sizeof(CellTrie) + pArray->map.mem_usage();

 		} else {

 			TrieSnapshot *snapshot = (TrieSnapshot *)object;

 			*pSize = sizeof(TrieSnapshot) + snapshot->mem_usage();

 		}

 		return true;

 	}

 } s_CellTrieHelpers;

 static cell_t CreateTrie(IPluginContext *pContext, const cell_t *params)

 {

 	CellTrie *pTrie = new CellTrie;

 	Handle_t hndl;

 	if ((hndl = handlesys->CreateHandle(htCellTrie, pTrie, pContext->GetIdentity(), g_pCoreIdent, NULL))

 		== BAD_HANDLE)

 	{

 		delete pTrie;

 		return BAD_HANDLE;

 	}

 	return hndl;

 }

 static cell_t SetTrieValue(IPluginContext *pContext, const cell_t *params)

 {

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	char *key;

 	pContext->LocalToString(params[2], &key);

 	StringHashMap<Entry>::Insert i = pTrie->map.findForAdd(key);

 	if (!i.found())

 	{

 		if (!pTrie->map.add(i, key))

 			return 0;

 		i->value.setCell(params[3]);

 		return 1;

 	}

 	if (!params[4])

 		return 0;

 	i->value.setCell(params[3]);

 	return 1;

 }

 static cell_t SetTrieArray(IPluginContext *pContext, const cell_t *params)

 {

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	if (params[4] < 0)

 	{

 		return pContext->ThrowNativeError("Invalid array size: %d", params[4]);

 	}

 	char *key;

 	cell_t *array;

 	pContext->LocalToString(params[2], &key);

 	pContext->LocalToPhysAddr(params[3], &array);

 	StringHashMap<Entry>::Insert i = pTrie->map.findForAdd(key);

 	if (!i.found())

 	{

 		if (!pTrie->map.add(i, key))

 			return 0;

 		i->key = key;

 		i->value.setArray(array, params[4]);

 		return 1;

 	}

 	if (!params[4])

 		return 0;

 	i->value.setArray(array, params[4]);

 	return 1;

 }

 static cell_t SetTrieString(IPluginContext *pContext, const cell_t *params)

 {

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	char *key, *val;

 	pContext->LocalToString(params[2], &key);

 	pContext->LocalToString(params[3], &val);

 	StringHashMap<Entry>::Insert i = pTrie->map.findForAdd(key);

 	if (!i.found())

 	{

 		if (!pTrie->map.add(i, key))

 			return 0;

 		i->value.setString(val);

 		return 1;

 	}

 	if (!params[4])

 		return 0;

 	i->value.setString(val);

 	return 1;

 }

 static cell_t RemoveFromTrie(IPluginContext *pContext, const cell_t *params)

 {

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	char *key;

 	pContext->LocalToString(params[2], &key);

 	StringHashMap<Entry>::Result r = pTrie->map.find(key);

 	if (!r.found())

 		return 0;

 	pTrie->map.remove(r);

 	return 1;

 }

 static cell_t ClearTrie(IPluginContext *pContext, const cell_t *params)

 {

 	Handle_t hndl;

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	pTrie->map.clear();

 	return 1;

 }

 static cell_t GetTrieValue(IPluginContext *pContext, const cell_t *params)

 {

 	Handle_t hndl;

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	char *key;

 	cell_t *pValue;

 	pContext->LocalToString(params[2], &key);

 	pContext->LocalToPhysAddr(params[3], &pValue);

 	StringHashMap<Entry>::Result r = pTrie->map.find(key);

 	if (!r.found())

 		return 0;

 	if (r->value.isCell())

 	{

 		*pValue = r->value.cell();

 		return 1;

 	}

 	// Maintain compatibility with an old bug. If an array was set with one

 	// cell, it was stored internally as a single cell. We now store as an

 	// actual array, but we make GetTrieValue() still work for this case.

 	if (r->value.isArray() && r->value.arrayLength() == 1)

 	{

 		*pValue = r->value.array()[0];

 		return 1;

 	}

 	return 0;

 }

 static cell_t GetTrieArray(IPluginContext *pContext, const cell_t *params)

 {

 	Handle_t hndl;

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	if (params[4] < 0)

 	{

 		return pContext->ThrowNativeError("Invalid array size: %d", params[4]);

 	}

 	char *key;

 	cell_t *pValue, *pSize;

 	pContext->LocalToString(params[2], &key);

 	pContext->LocalToPhysAddr(params[3], &pValue);

 	pContext->LocalToPhysAddr(params[5], &pSize);

 	StringHashMap<Entry>::Result r = pTrie->map.find(key);

 	if (!r.found() || !r->value.isArray())

 		return 0;

 	if (!r->value.array())

 	{

 		*pSize = 0;

 		return 1;

 	}

 	if (!params[4])

 		return 1;

 	size_t length = r->value.arrayLength();

 	cell_t *base = r->value.array();

 	if (length > size_t(params[4]))

 		*pSize = params[4];

 	else

 		*pSize = length;

 	memcpy(pValue, base, sizeof(cell_t) * pSize[0]);

 	return 1;

 }

 static cell_t GetTrieString(IPluginContext *pContext, const cell_t *params)

 {

 	Handle_t hndl;

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	if (params[4] < 0)

 	{

 		return pContext->ThrowNativeError("Invalid buffer size: %d", params[4]);

 	}

 	char *key;

 	cell_t *pSize;

 	pContext->LocalToString(params[2], &key);

 	pContext->LocalToPhysAddr(params[5], &pSize);

 	StringHashMap<Entry>::Result r = pTrie->map.find(key);

 	if (!r.found() || !r->value.isString())

 		return 0;

 	size_t written;

 	pContext->StringToLocalUTF8(params[3], params[4], r->value.chars(), &written);

 	*pSize = (cell_t)written;

 	return 1;

 }

 static cell_t GetTrieSize(IPluginContext *pContext, const cell_t *params)

 {

 	Handle_t hndl;

 	CellTrie *pTrie;

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	hndl = params[1];

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	return pTrie->map.elements();

 }

 static cell_t CreateTrieSnapshot(IPluginContext *pContext, const cell_t *params)

 {

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	CellTrie *pTrie;

 	if ((err = handlesys->ReadHandle(hndl, htCellTrie, &sec, (void **)&pTrie))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	TrieSnapshot *snapshot = new TrieSnapshot;

 	snapshot->length = pTrie->map.elements();

 	snapshot->keys = new int[snapshot->length];

 	size_t i = 0;

 	for (StringHashMap<Entry>::iterator iter = pTrie->map.iter(); !iter.empty(); iter.next(), i++)

 		snapshot->keys[i] = snapshot->strings.AddString(iter->key.chars(), iter->key.length());

 	assert(i == snapshot->length);

 	if ((hndl = handlesys->CreateHandle(htSnapshot, snapshot, pContext->GetIdentity(), g_pCoreIdent, NULL))

 		== BAD_HANDLE)

 	{

 		delete snapshot;

 		return BAD_HANDLE;

 	}

 	return hndl;

 }

 static cell_t TrieSnapshotLength(IPluginContext *pContext, const cell_t *params)

 {

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	TrieSnapshot *snapshot;

 	if ((err = handlesys->ReadHandle(hndl, htSnapshot, &sec, (void **)&snapshot))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	return snapshot->length;

 }

 static cell_t TrieSnapshotKeyBufferSize(IPluginContext *pContext, const cell_t *params)

 {

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	TrieSnapshot *snapshot;

 	if ((err = handlesys->ReadHandle(hndl, htSnapshot, &sec, (void **)&snapshot))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	unsigned index = params[2];

 	if (index >= snapshot->length)

 		return pContext->ThrowNativeError("Invalid index %d", index);

 	return strlen(snapshot->strings.GetString(snapshot->keys[index])) + 1;

 }

 static cell_t GetTrieSnapshotKey(IPluginContext *pContext, const cell_t *params)

 {

 	HandleError err;

 	HandleSecurity sec = HandleSecurity(pContext->GetIdentity(), g_pCoreIdent);

 	Handle_t hndl = params[1];

 	TrieSnapshot *snapshot;

 	if ((err = handlesys->ReadHandle(hndl, htSnapshot, &sec, (void **)&snapshot))

 		!= HandleError_None)

 	{

 		return pContext->ThrowNativeError("Invalid Handle %x (error %d)", hndl, err);

 	}

 	unsigned index = params[2];

 	if (index >= snapshot->length)

 		return pContext->ThrowNativeError("Invalid index %d", index);

 	size_t written;

 	const char *str = snapshot->strings.GetString(snapshot->keys[index]);

 	pContext->StringToLocalUTF8(params[3], params[4], str, &written);

 	return written;

 }

 REGISTER_NATIVES(trieNatives)

 {

 	{"ClearTrie",				ClearTrie},

 	{"CreateTrie",				CreateTrie},

 	{"GetTrieArray",			GetTrieArray},

 	{"GetTrieString",			GetTrieString},

 	{"GetTrieValue",			GetTrieValue},

 	{"RemoveFromTrie",			RemoveFromTrie},

 	{"SetTrieArray",			SetTrieArray},

 	{"SetTrieString",			SetTrieString},

 	{"SetTrieValue",			SetTrieValue},

 	{"GetTrieSize",				GetTrieSize},

 	{"CreateTrieSnapshot",		CreateTrieSnapshot},

 	{"TrieSnapshotLength",		TrieSnapshotLength},

 	{"TrieSnapshotKeyBufferSize", TrieSnapshotKeyBufferSize},

 	{"GetTrieSnapshotKey",		GetTrieSnapshotKey},

 	{NULL,						NULL},

 };