Add functions for working with entity lumps

bridge/include/LogicProvider.h

@@ -73,6 +73,9 @@ struct sm_logic_t
 	void            (*FreeCellArray)(ICellArray *arr);
 	void *			(*FromPseudoAddress)(uint32_t pseudoAddr);
 	uint32_t		(*ToPseudoAddress)(void *addr);
+	void			(*SetEntityLumpWritable)(bool writable);
+	bool			(*ParseEntityLumpString)(const char *entityString, int &status, size_t &position);
+	const char *	(*GetEntityLumpString)();
 	IScriptManager	*scripts;
 	IShareSys		*sharesys;
 	IExtensionSys	*extsys;

core/logic/AMBuilder

@@ -84,6 +84,8 @@ for cxx in builder.targets:
     'smn_halflife.cpp',
     'FrameIterator.cpp',
     'DatabaseConfBuilder.cpp',
+    'LumpManager.cpp',
+    'smn_entitylump.cpp',
   ]
 
   if binary.compiler.target.arch == 'x86_64':

core/logic/LumpManager.cpp

@@ -0,0 +1,133 @@
+/**
+ * vim: set ts=4 :
+ * =============================================================================
+ * Entity Lump Manager
+ * Copyright (C) 2021-2022 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 "LumpManager.h"
+
+#include <iomanip>
+#include <sstream>
+
+EntityLumpParseResult::operator bool() const {
+	return m_Status == Status_OK;
+}
+
+EntityLumpParseResult EntityLumpManager::Parse(const char* pMapEntities) {
+	m_Entities.clear();
+
+	std::istringstream mapEntities(pMapEntities);
+
+	for (;;) {
+		std::string token;
+		mapEntities >> std::ws >> token >> std::ws;
+
+		// Assert that we're at the start of a new block, otherwise we're done parsing
+		if (token != "{") {
+			if (token == "\0") {
+				break;
+			} else {
+				return EntityLumpParseResult {
+					Status_UnexpectedChar, mapEntities.tellg()
+				};
+			}
+		}
+
+		/**
+		 * Parse key / value pairs until we reach a closing brace.  We currently assume there
+		 * are only quoted keys / values up to the next closing brace.
+		 *
+		 * The SDK suggests that there are cases that could use non-quoted symbols and nested
+		 * braces (`shared/mapentities_shared.cpp::MapEntity_ParseToken`), but I haven't seen
+		 * those in practice.
+		 */
+		EntityLumpEntry entry;
+		while (mapEntities.peek() != '}') {
+			std::string key, value;
+
+			if (mapEntities.peek() != '"') {
+				return EntityLumpParseResult {
+					Status_UnexpectedChar, mapEntities.tellg()
+				};
+			}
+			mapEntities >> quoted(key) >> std::ws;
+
+			if (mapEntities.peek() != '"') {
+				return EntityLumpParseResult {
+					Status_UnexpectedChar, mapEntities.tellg()
+				};
+			}
+			mapEntities >> quoted(value) >> std::ws;
+
+			entry.emplace_back(key, value);
+		}
+		mapEntities.get();
+		m_Entities.push_back(std::make_shared<EntityLumpEntry>(entry));
+	}
+
+	return EntityLumpParseResult{};
+}
+
+std::string EntityLumpManager::Dump() {
+	std::ostringstream stream;
+	for (const auto& entry : m_Entities) {
+		// ignore empty entries
+		if (entry->empty()) {
+			continue;
+		}
+		stream << "{\n";
+		for (const auto& pair : *entry) {
+			stream << '"' << pair.first << "\"	\"" << pair.second << '"' << '\n';
+		}
+		stream << "}\n";
+	}
+	return stream.str();
+}
+
+std::weak_ptr<EntityLumpEntry> EntityLumpManager::Get(size_t index) {
+	return m_Entities[index];
+}
+
+void EntityLumpManager::Erase(size_t index) {
+	m_Entities.erase(m_Entities.begin() + index);
+}
+
+void EntityLumpManager::Insert(size_t index) {
+	m_Entities.emplace(m_Entities.begin() + index, std::make_shared<EntityLumpEntry>());
+}
+
+size_t EntityLumpManager::Append() {
+	return std::distance(
+			m_Entities.begin(),
+			m_Entities.emplace(m_Entities.end(), std::make_shared<EntityLumpEntry>())
+	);
+}
+
+size_t EntityLumpManager::Length() {
+	return m_Entities.size();
+}

core/logic/LumpManager.h

@@ -0,0 +1,116 @@
+/**
+ * vim: set ts=4 :
+ * =============================================================================
+ * Entity Lump Manager
+ * Copyright (C) 2021-2022 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: $Id$
+ */
+
+#ifndef _INCLUDE_LUMPMANAGER_H_
+#define _INCLUDE_LUMPMANAGER_H_
+
+#include <vector>
+#include <memory>
+#include <string>
+
+/**
+ * Entity lump manager.  Provides a list that stores a list of key / value pairs and the
+ * functionality to (de)serialize it from / to an entity string.
+ * This file and its corresponding .cpp should be compilable independently of SourceMod;
+ * the SourceMod interop is located within smn_entitylump.
+ *
+ * @file lumpmanager.h
+ * @brief Class definition for object that parses lumps.
+ */
+
+/**
+ * @brief A container of key / value pairs.
+ */
+using EntityLumpEntry = std::vector<std::pair<std::string, std::string>>;
+
+enum EntityLumpParseStatus {
+	Status_OK,
+	Status_UnexpectedChar,
+};
+
+/**
+ * @brief Result of parsing an entity lump.  On a parse error, m_Status is not Status_OK and
+ * m_Position indicates the offset within the string that caused the parse error.
+ */
+struct EntityLumpParseResult {
+	EntityLumpParseStatus m_Status;
+	std::streamoff m_Position;
+
+	operator bool() const;
+	const char* Description() const;
+};
+
+/**
+ * @brief Manages entity lump entries.
+ */
+class EntityLumpManager
+{
+public:
+	/**
+	 * @brief Parses the map entities string into an internal representation.
+	 */
+	EntityLumpParseResult Parse(const char* pMapEntities);
+
+	/**
+	 * @brief Dumps the current internal representation out to an std::string.
+	 */
+	std::string Dump();
+
+	/**
+	 * @brief Returns a weak reference to an EntityLumpEntry.  Used for handles on the scripting side.
+	 */
+	std::weak_ptr<EntityLumpEntry> Get(size_t index);
+
+	/**
+	 * @brief Removes an EntityLumpEntry at the given index, shifting down all entries after it by one.
+	 */
+	void Erase(size_t index);
+
+	/**
+	 * @brief Inserts a new EntityLumpEntry at the given index, shifting up the entries previously at the index and after it up by one.
+	 */
+	void Insert(size_t index);
+
+	/**
+	 * @brief Adds a new EntityLumpEntry to the end.  Returns the index of the entry.
+	 */
+	size_t Append();
+
+	/**
+	 * @brief Returns the number of EntityLumpEntry items in the list.
+	 */
+	size_t Length();
+
+private:
+	std::vector<std::shared_ptr<EntityLumpEntry>> m_Entities;
+};
+
+#endif // _INCLUDE_LUMPMANAGER_H_

core/logic/common_logic.cpp

@@ -56,6 +56,7 @@
 #include "LibrarySys.h"
 #include "RootConsoleMenu.h"
 #include "CellArray.h"
+#include "smn_entitylump.h"
 #include <bridge/include/BridgeAPI.h>
 #include <bridge/include/IProviderCallbacks.h>
 
@@ -135,6 +136,35 @@ static uint32_t ToPseudoAddress(void *addr)
 #endif
 }
 
+static void SetEntityLumpWritable(bool writable)
+{
+	g_bLumpAvailableForWriting = writable;
+
+	// write-lock causes the map entities to be serialized out to string
+	if (!writable)
+	{
+		g_strMapEntities = lumpmanager->Dump();
+	}
+}
+
+static bool ParseEntityLumpString(const char *pMapEntities, int &status, size_t &position)
+{
+	EntityLumpParseResult result = lumpmanager->Parse(pMapEntities);
+	status = static_cast<int>(result.m_Status);
+	position = static_cast<size_t>(result.m_Position);
+	return result;
+}
+
+// returns nullptr if the original lump failed to parse
+static const char* GetEntityLumpString()
+{
+	if (g_strMapEntities.empty())
+	{
+		return nullptr;
+	}
+	return g_strMapEntities.c_str();
+}
+
 // Defined in smn_filesystem.cpp.
 extern bool OnLogPrint(const char *msg);
 
@@ -170,6 +200,9 @@ static sm_logic_t logic =
 	CellArray::Free,
 	FromPseudoAddress,
 	ToPseudoAddress,
+	SetEntityLumpWritable,
+	ParseEntityLumpString,
+	GetEntityLumpString,
 	&g_PluginSys,
 	&g_ShareSys,
 	&g_Extensions,

core/logic/smn_entitylump.cpp

@@ -0,0 +1,367 @@
+/**
+ * vim: set ts=4 :
+ * =============================================================================
+ * Entity Lump Manager
+ * Copyright (C) 2021-2022 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 "HandleSys.h"
+#include "common_logic.h"
+
+#include "LumpManager.h"
+
+#include <algorithm>
+
+HandleType_t g_EntityLumpEntryType;
+
+std::string g_strMapEntities;
+bool g_bLumpAvailableForWriting = false;
+
+static EntityLumpManager s_LumpManager;
+EntityLumpManager *lumpmanager = &s_LumpManager;
+
+class LumpManagerNatives :
+	public IHandleTypeDispatch,
+	public SMGlobalClass
+{
+public: //SMGlobalClass
+	void OnSourceModAllInitialized()
+	{
+		g_EntityLumpEntryType = handlesys->CreateType("EntityLumpEntry", this, 0, NULL, NULL, g_pCoreIdent, NULL);
+	}
+	void OnSourceModShutdown()
+	{
+		handlesys->RemoveType(g_EntityLumpEntryType, g_pCoreIdent);
+	}
+public: //IHandleTypeDispatch
+	void OnHandleDestroy(HandleType_t type, void* object)
+	{
+		if (type == g_EntityLumpEntryType)
+		{
+			delete reinterpret_cast<std::weak_ptr<EntityLumpEntry>*>(object);
+		}
+	}
+};
+
+static LumpManagerNatives s_LumpManagerNatives;
+
+cell_t sm_LumpManagerGet(IPluginContext *pContext, const cell_t *params) {
+	int index = params[1];
+	if (index < 0 || index >= static_cast<int>(lumpmanager->Length())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	std::weak_ptr<EntityLumpEntry>* pReference = new std::weak_ptr<EntityLumpEntry>;
+	*pReference = lumpmanager->Get(index);
+
+	return handlesys->CreateHandle(g_EntityLumpEntryType, pReference,
+			pContext->GetIdentity(), g_pCoreIdent, NULL);
+}
+
+cell_t sm_LumpManagerErase(IPluginContext *pContext, const cell_t *params) {
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLump.Erase() outside of OnMapInit");
+	}
+
+	int index = params[1];
+	if (index < 0 || index >= static_cast<int>(lumpmanager->Length())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	lumpmanager->Erase(index);
+	return 0;
+}
+
+cell_t sm_LumpManagerInsert(IPluginContext *pContext, const cell_t *params) {
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLump.Insert() outside of OnMapInit");
+	}
+
+	int index = params[1];
+	if (index < 0 || index > static_cast<int>(lumpmanager->Length())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	lumpmanager->Insert(index);
+	return 0;
+}
+
+cell_t sm_LumpManagerAppend(IPluginContext *pContext, const cell_t *params) {
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLump.Append() outside of OnMapInit");
+	}
+	return lumpmanager->Append();
+}
+
+cell_t sm_LumpManagerLength(IPluginContext *pContext, const cell_t *params) {
+	return lumpmanager->Length();
+}
+
+cell_t sm_LumpEntryGet(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	auto entry = entryref->lock();
+
+	int index = params[2];
+	if (index < 0 || index >= static_cast<int>(entry->size())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	const auto& pair = (*entry)[index];
+
+	size_t nBytes;
+	pContext->StringToLocalUTF8(params[3], params[4], pair.first.c_str(), &nBytes);
+	pContext->StringToLocalUTF8(params[5], params[6], pair.second.c_str(), &nBytes);
+
+	return 0;
+}
+
+cell_t sm_LumpEntryUpdate(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLumpEntry.Update() outside of OnMapInit");
+	}
+
+	auto entry = entryref->lock();
+
+	int index = params[2];
+	if (index < 0 || index >= static_cast<int>(entry->size())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	char *key, *value;
+	pContext->LocalToStringNULL(params[3], &key);
+	pContext->LocalToStringNULL(params[4], &value);
+
+	auto& pair = (*entry)[index];
+	if (key != nullptr) {
+		pair.first = key;
+	}
+	if (value != nullptr) {
+		pair.second = value;
+	}
+
+	return 0;
+}
+
+cell_t sm_LumpEntryInsert(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLumpEntry.Insert() outside of OnMapInit");
+	}
+
+	auto entry = entryref->lock();
+
+	int index = params[2];
+	if (index < 0 || index > static_cast<int>(entry->size())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	char *key, *value;
+	pContext->LocalToString(params[3], &key);
+	pContext->LocalToString(params[4], &value);
+
+	entry->emplace(entry->begin() + index, key, value);
+
+	return 0;
+}
+
+cell_t sm_LumpEntryErase(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLumpEntry.Erase() outside of OnMapInit");
+	}
+
+	auto entry = entryref->lock();
+
+	int index = params[2];
+	if (index < 0 || index >= static_cast<int>(entry->size())) {
+		return pContext->ThrowNativeError("Invalid index %d", index);
+	}
+
+	entry->erase(entry->begin() + index);
+
+	return 0;
+}
+
+cell_t sm_LumpEntryAppend(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	if (!g_bLumpAvailableForWriting) {
+		return pContext->ThrowNativeError("Cannot use EntityLumpEntry.Append() outside of OnMapInit");
+	}
+
+	auto entry = entryref->lock();
+
+	char *key, *value;
+	pContext->LocalToString(params[2], &key);
+	pContext->LocalToString(params[3], &value);
+
+	entry->emplace_back(key, value);
+
+	return 0;
+}
+
+cell_t sm_LumpEntryFindKey(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	// start from the index after the current one
+	int start = params[3] + 1;
+
+	auto entry = entryref->lock();
+
+	if (start < 0 || start >= static_cast<int>(entry->size())) {
+		return -1;
+	}
+
+	char *key;
+	pContext->LocalToString(params[2], &key);
+
+	auto matches_key = [&key](std::pair<std::string,std::string> pair) {
+		return pair.first == key;
+	};
+
+	auto result = std::find_if(entry->begin() + start, entry->end(), matches_key);
+
+	if (result == entry->end()) {
+		return -1;
+	}
+	return std::distance(entry->begin(), result);
+}
+
+cell_t sm_LumpEntryLength(IPluginContext *pContext, const cell_t *params) {
+	HandleSecurity sec(pContext->GetIdentity(), g_pCoreIdent);
+	HandleError err;
+
+	Handle_t hndl = static_cast<Handle_t>(params[1]);
+
+	std::weak_ptr<EntityLumpEntry>* entryref = nullptr;
+	if ((err = handlesys->ReadHandle(hndl, g_EntityLumpEntryType, &sec, (void**) &entryref)) != HandleError_None) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (error: %d)", hndl, err);
+	}
+
+	if (entryref->expired()) {
+		return pContext->ThrowNativeError("Invalid EntityLumpEntry handle %x (reference expired)", hndl);
+	}
+
+	auto entry = entryref->lock();
+	return entry->size();
+}
+
+REGISTER_NATIVES(entityLumpNatives)
+{
+	{ "EntityLump.Get", sm_LumpManagerGet },
+	{ "EntityLump.Erase", sm_LumpManagerErase },
+	{ "EntityLump.Insert", sm_LumpManagerInsert },
+	{ "EntityLump.Append", sm_LumpManagerAppend },
+	{ "EntityLump.Length", sm_LumpManagerLength },
+
+	{ "EntityLumpEntry.Get", sm_LumpEntryGet },
+	{ "EntityLumpEntry.Update", sm_LumpEntryUpdate },
+	{ "EntityLumpEntry.Insert", sm_LumpEntryInsert },
+	{ "EntityLumpEntry.Erase", sm_LumpEntryErase },
+	{ "EntityLumpEntry.Append", sm_LumpEntryAppend },
+	{ "EntityLumpEntry.FindKey", sm_LumpEntryFindKey },
+	{ "EntityLumpEntry.Length.get", sm_LumpEntryLength },
+
+	{NULL, NULL}
+};

core/logic/smn_entitylump.h

@@ -0,0 +1,44 @@
+/**
+* vim: set ts=4 :
+* =============================================================================
+* SourceMod
+* Copyright (C) 2022-2022 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: $Id$
+*/
+
+#ifndef _INCLUDE_SOURCEMOD_ENTITYLUMP_H_
+#define _INCLUDE_SOURCEMOD_ENTITYLUMP_H_
+
+#include <IHandleSys.h>
+#include "LumpManager.h"
+
+using namespace SourceMod;
+
+extern std::string g_strMapEntities;
+extern bool g_bLumpAvailableForWriting;
+extern EntityLumpManager *lumpmanager;
+
+#endif // _INCLUDE_SOURCEMOD_ENTITYLUMP_H_

core/sourcemod.cpp

@@ -54,6 +54,7 @@ SH_DECL_HOOK0_void(IServerGameDLL, LevelShutdown, SH_NOATTRIB, false);
 SH_DECL_HOOK1_void(IServerGameDLL, GameFrame, SH_NOATTRIB, false, bool);
 SH_DECL_HOOK1_void(IServerGameDLL, Think, SH_NOATTRIB, false, bool);
 SH_DECL_HOOK1_void(IVEngineServer, ServerCommand, SH_NOATTRIB, false, const char *);
+SH_DECL_HOOK0(IVEngineServer, GetMapEntitiesString, SH_NOATTRIB, 0, const char *);
 
 SourceModBase g_SourceMod;
 
@@ -278,6 +279,7 @@ bool SourceModBase::InitializeSourceMod(char *error, size_t maxlength, bool late
 
 	/* Hook this now so we can detect startup without calling StartSourceMod() */
 	SH_ADD_HOOK(IServerGameDLL, LevelInit, gamedll, SH_MEMBER(this, &SourceModBase::LevelInit), false);
+	SH_ADD_HOOK(IVEngineServer, GetMapEntitiesString, engine, SH_MEMBER(this, &SourceModBase::GetMapEntitiesString), false);
 
 	/* Only load if we're not late */
 	if (!late)
@@ -416,10 +418,32 @@ bool SourceModBase::LevelInit(char const *pMapName, char const *pMapEntities, ch
 
 	g_LevelEndBarrier = true;
 
+	int parseError;
+	size_t position;
+	bool success = logicore.ParseEntityLumpString(pMapEntities, parseError, position);
+
+	logicore.SetEntityLumpWritable(true);
 	g_pOnMapInit->PushString(pMapName);
 	g_pOnMapInit->Execute();
+	logicore.SetEntityLumpWritable(false);
 
-	RETURN_META_VALUE(MRES_IGNORED, true);
+	if (!success)
+	{
+		logger->LogError("Map entity lump parsing for %s failed with error code %d on position %d", pMapName, parseError, position);
+		RETURN_META_VALUE(MRES_IGNORED, true);
+	}
+
+	RETURN_META_VALUE_NEWPARAMS(MRES_HANDLED, true, &IServerGameDLL::LevelInit, (pMapName, logicore.GetEntityLumpString(), pOldLevel, pLandmarkName, loadGame, background));
+}
+
+const char *SourceModBase::GetMapEntitiesString()
+{
+	const char *pNewMapEntities = logicore.GetEntityLumpString();
+	if (pNewMapEntities != nullptr)
+	{
+		RETURN_META_VALUE(MRES_SUPERCEDE, pNewMapEntities);
+	}
+	RETURN_META_VALUE(MRES_IGNORED, NULL);
 }
 
 void SourceModBase::LevelShutdown()
@@ -534,6 +558,7 @@ void SourceModBase::CloseSourceMod()
 		return;
 
 	SH_REMOVE_HOOK(IServerGameDLL, LevelInit, gamedll, SH_MEMBER(this, &SourceModBase::LevelInit), false);
+	SH_REMOVE_HOOK(IVEngineServer, GetMapEntitiesString, engine, SH_MEMBER(this, &SourceModBase::GetMapEntitiesString), false);
 
 	if (g_Loaded)
 	{

core/sourcemod.h

@@ -140,6 +140,7 @@ class SourceModBase :
 private:
 	void ShutdownServices();
 private:
+	const char* GetMapEntitiesString();
 	char m_SMBaseDir[PLATFORM_MAX_PATH];
 	char m_SMRelDir[PLATFORM_MAX_PATH];
 	char m_ModDir[32];

plugins/include/entitylump.inc

@@ -0,0 +1,118 @@
+#if defined _entitylump_included
+	#endinput
+#endif
+
+#define _entitylump_included
+
+/**
+ * A handle to a weakref of an ordered list of key / value pairs; any write operations on this handle will affect the resulting map entity string.
+ * If the entry in the EntityLump is removed, the handle will error on all operations.
+ * (The handle will remain valid on the scripting side, and will still need to be deleted.)
+ */
+methodmap EntityLumpEntry < Handle {
+	/**
+	 * Copies the key / value at the given index into buffers.
+	 *
+	 * @error Index is out of bounds.
+	 */
+	public native void Get(int index, char[] keybuf = "", int keylen = 0, char[] valbuf = "", int vallen = 0);
+
+	/**
+	 * Updates the key / value pair at the given index.
+	 * NULL_STRING may be used to preserve the existing value.
+	 *
+	 * @error Index is out of bounds or entity lump is read-only.
+	 */
+	public native void Update(int index, const char[] key = NULL_STRING, const char[] value = NULL_STRING);
+
+	/**
+	 * Inserts a new key / value pair at the given index, shifting the pair at that index and beyond up.
+	 * If EntityLumpEntry.Length is passed in, this is an append operation.
+	 *
+	 * @error Index is out of bounds or entity lump is read-only.
+	 */
+	public native void Insert(int index, const char[] key, const char[] value);
+
+	/**
+	 * Removes the key / value pair at the given index, shifting all entries past it down.
+	 *
+	 * @error Index is out of bounds or entity lump is read-only.
+	 */
+	public native void Erase(int index);
+
+	/**
+	 * Inserts a new key / value pair at the end.
+	 *
+	 * @error Index is out of bounds or entity lump is read-only.
+	 */
+	public native void Append(const char[] key, const char[] value);
+
+	/**
+	 * Returns the first index after `start` with the matching key, or -1 if not found.
+	 */
+	public native int FindKey(const char[] key, int start = -1);
+
+	/**
+	 * Returns the first index after `start` with the matching key, or -1 if not found.
+	 * This also copies the value from that index into the given buffer.
+	 *
+	 * @error `start` is out of bounds and not -1.
+	 */
+	public int GetNextKey(const char[] key, char[] buffer, int maxlen, int start = -1) {
+		int result = this.FindKey(key, start);
+		if (result != -1) {
+			this.Get(result, .valbuf = buffer, .vallen = maxlen);
+		} else {
+			buffer[0] = '\0';
+		}
+		return result;
+	}
+
+	/**
+	 * Returns the number of key / value pairs in the list.
+	 */
+	property int Length {
+		public native get();
+	}
+};
+
+/**
+ * A group of natives for a singleton entity lump.
+ * EntityLumpEntry instances are only available for writing during OnMapInit().
+ */
+methodmap EntityLump {
+	/**
+	 * Returns the EntityLumpEntry at the given index.
+	 * This handle should be freed by the calling plugin.
+	 *
+	 * @error Index is out of bounds.
+	 */
+	public static native EntityLumpEntry Get(int index);
+
+	/**
+	 * Erases an EntityLumpEntry at the given index, shifting all entries past it down.
+	 * Any handles referencing the erased EntityLumpEntry will throw on any operations aside from delete.
+	 *
+	 * @error Index is out of bounds or entity lump is read-only.
+	 */
+	public static native void Erase(int index);
+
+	/**
+	 * Inserts an empty EntityLumpEntry at the given index, shifting the existing entry and ones past it up.
+	 *
+	 * @error Index is out of bounds or entity lump is read-only.
+	 */
+	public static native void Insert(int index);
+
+	/**
+	 * Creates an empty EntityLumpEntry, returning its index.
+	 *
+	 * @error Entity lump is read-only.
+	 */
+	public static native int Append();
+
+	/**
+	 * Returns the number of entities currently in the lump.
+	 */
+	public static native int Length();
+};

plugins/include/sourcemod.inc

@@ -76,6 +76,7 @@ struct Plugin
 #include <commandfilters>
 #include <nextmap>
 #include <commandline>
+#include <entitylump>
 
 enum APLRes
 {

plugins/testsuite/entitylumptest.sp

@@ -0,0 +1,125 @@
+#pragma semicolon 1
+#include <sourcemod>
+
+#include <sdktools>
+#include <entitylump>
+
+#pragma newdecls required
+
+#define PLUGIN_VERSION "0.0.0"
+public Plugin myinfo = {
+	name = "Entity Lump Core Native Test",
+	author = "nosoop",
+	description = "A port of the Level KeyValues entity test to the Entity Lump implementation in core SourceMod",
+}
+
+#define OUTPUT_NAME "OnCapTeam2"
+
+public void OnMapInit() {
+	// set every area_time_to_cap value to 30
+	for (int i, n = EntityLump.Length(); i < n; i++) {
+		EntityLumpEntry entry = EntityLump.Get(i);
+
+		int ttc = entry.FindKey("area_time_to_cap");
+		if (ttc != -1) {
+			entry.Update(ttc, NULL_STRING, "30");
+			PrintToServer("Set time to cap for item %d to 30", i);
+		}
+
+		delete entry;
+	}
+}
+
+public void OnMapStart() {
+	int captureArea = FindEntityByClassname(-1, "trigger_capture_area");
+
+	if (!IsValidEntity(captureArea)) {
+		LogMessage("---- %s", "No capture area");
+		return;
+	}
+
+	int hammerid = GetEntProp(captureArea, Prop_Data, "m_iHammerID");
+	EntityLumpEntry entry = FindEntityLumpEntryByHammerID(hammerid);
+
+	if (!entry) {
+		return;
+	}
+
+	LogMessage("---- %s", "Found a trigger_capture_area with keys:");
+
+	for (int i, n = entry.Length; i < n; i++) {
+		char keyBuffer[128], valueBuffer[128];
+		entry.Get(i, keyBuffer, sizeof(keyBuffer), valueBuffer, sizeof(valueBuffer));
+
+		LogMessage("%s -> %s", keyBuffer, valueBuffer);
+	}
+
+	LogMessage("---- %s", "List of " ... OUTPUT_NAME ... " outputs:");
+	char outputString[256];
+	for (int k = -1; (k = entry.GetNextKey(OUTPUT_NAME, outputString, sizeof(outputString), k)) != -1;) {
+		char targetName[32], inputName[64], variantValue[32];
+		float delay;
+		int nFireCount;
+
+		ParseEntityOutputString(outputString, targetName, sizeof(targetName),
+				inputName, sizeof(inputName), variantValue, sizeof(variantValue),
+				delay, nFireCount);
+
+		LogMessage("target %s -> input %s (value %s, delay %.2f, refire %d)",
+				targetName, inputName, variantValue, delay, nFireCount);
+	}
+	delete entry;
+}
+
+/**
+ * Returns the first EntityLumpEntry with a matching hammerid.
+ */
+EntityLumpEntry FindEntityLumpEntryByHammerID(int hammerid) {
+	for (int i, n = EntityLump.Length(); i < n; i++) {
+		EntityLumpEntry entry = EntityLump.Get(i);
+
+		char value[32];
+		if (entry.GetNextKey("hammerid", value, sizeof(value)) != -1
+				&& StringToInt(value) == hammerid) {
+			return entry;
+		}
+		delete entry;
+	}
+	return null;
+}
+
+/**
+ * Parses an entity's output value (as formatted in the entity string).
+ * Refer to https://developer.valvesoftware.com/wiki/AddOutput for the format.
+ * 
+ * @return True if the output string was successfully parsed, false if not.
+ */
+stock bool ParseEntityOutputString(const char[] output, char[] targetName, int targetNameLength,
+		char[] inputName, int inputNameLength, char[] variantValue, int variantValueLength,
+		float &delay, int &nFireCount) {
+	int delimiter;
+	char buffer[32];
+
+	{
+		// validate that we have something resembling an output string (four commas)
+		int i, c, nDelim;
+		while ((c = FindCharInString(output[i], ',')) != -1) {
+			nDelim++;
+			i += c + 1;
+		}
+		if (nDelim < 4) {
+			return false;
+		}
+	}
+
+	delimiter = SplitString(output, ",", targetName, targetNameLength);
+	delimiter += SplitString(output[delimiter], ",", inputName, inputNameLength);
+	delimiter += SplitString(output[delimiter], ",", variantValue, variantValueLength);
+
+	delimiter += SplitString(output[delimiter], ",", buffer, sizeof(buffer));
+	delay = StringToFloat(buffer);
+
+	nFireCount = StringToInt(output[delimiter]);
+
+	return true;
+}

tools/entlumpparser/AMBuildScript

@@ -0,0 +1,224 @@
+# vim: set sts=2 ts=8 sw=2 tw=99 et ft=python:
+import os, sys
+
+# Simple extensions do not need to modify this file.
+
+def ResolveEnvPath(env, folder):
+  if env in os.environ:
+    path = os.environ[env]
+    if os.path.isdir(path):
+      return path
+    return None
+
+  head = os.getcwd()
+  oldhead = None
+  while head != None and head != oldhead:
+    path = os.path.join(head, folder)
+    if os.path.isdir(path):
+      return path
+    oldhead = head
+    head, tail = os.path.split(head)
+
+  return None
+
+def Normalize(path):
+  return os.path.abspath(os.path.normpath(path))
+
+class ProgramConfig(object):
+  def __init__(self):
+    self.binaries = []
+    self.sm_root = None
+
+  @property
+  def tag(self):
+    if builder.options.debug == '1':
+      return 'Debug'
+    return 'Release'
+
+  def configure(self):
+    cxx = builder.DetectCompilers()
+
+    if builder.options.sm_path:
+      self.sm_root = builder.options.sm_path
+    if not self.sm_root or not os.path.isdir(self.sm_root):
+      raise Exception('Could not find a source copy of SourceMod')
+
+    if cxx.like('gcc'):
+      self.configure_gcc(cxx)
+    elif cxx.vendor == 'msvc':
+      self.configure_msvc(cxx)
+
+    # Optimization
+    if builder.options.opt == '1':
+      cxx.defines += ['NDEBUG']
+
+    # Debugging
+    if builder.options.debug == '1':
+      cxx.defines += ['DEBUG', '_DEBUG']
+
+    # Platform-specifics
+    if builder.target_platform == 'linux':
+      self.configure_linux(cxx)
+    elif builder.target_platform == 'mac':
+      self.configure_mac(cxx)
+    elif builder.target_platform == 'windows':
+      self.configure_windows(cxx)
+
+    # Finish up.
+    cxx.includes += [
+      os.path.join(self.sm_root, 'public'),
+    ]
+
+  def configure_gcc(self, cxx):
+    cxx.defines += [
+      'stricmp=strcasecmp',
+      '_stricmp=strcasecmp',
+      '_snprintf=snprintf',
+      '_vsnprintf=vsnprintf',
+      'HAVE_STDINT_H',
+      'GNUC',
+    ]
+    cxx.cflags += [
+      '-pipe',
+      '-fno-strict-aliasing',
+      '-Wall',
+      '-Werror',
+      '-Wno-unused',
+      '-Wno-switch',
+      '-Wno-array-bounds',
+      '-msse',
+      '-m32',
+      '-fvisibility=hidden',
+    ]
+    cxx.cxxflags += [
+      '-std=c++14',
+      '-fno-exceptions',
+      '-fno-threadsafe-statics',
+      '-Wno-non-virtual-dtor',
+      '-Wno-overloaded-virtual',
+      '-fvisibility-inlines-hidden',
+    ]
+    cxx.linkflags += ['-m32']
+
+    have_gcc = cxx.vendor == 'gcc'
+    have_clang = cxx.vendor == 'clang'
+    if cxx.version >= 'clang-3.9' or cxx.version == 'clang-3.4' or cxx.version > 'apple-clang-6.0':
+      cxx.cxxflags += ['-Wno-expansion-to-defined']
+    if cxx.version >= 'clang-3.6':
+      cxx.cxxflags += ['-Wno-inconsistent-missing-override']
+    if have_clang or (cxx.version >= 'gcc-4.6'):
+      cxx.cflags += ['-Wno-narrowing']
+    if have_clang or (cxx.version >= 'gcc-4.7'):
+      cxx.cxxflags += ['-Wno-delete-non-virtual-dtor']
+    if cxx.version >= 'gcc-4.8':
+      cxx.cflags += ['-Wno-unused-result']
+
+    if have_clang:
+      cxx.cxxflags += ['-Wno-implicit-exception-spec-mismatch']
+      if cxx.version >= 'apple-clang-5.1' or cxx.version >= 'clang-3.4':
+        cxx.cxxflags += ['-Wno-deprecated-register']
+      else:
+        cxx.cxxflags += ['-Wno-deprecated']
+      cxx.cflags += ['-Wno-sometimes-uninitialized']
+
+    if have_gcc:
+      cxx.cflags += ['-mfpmath=sse']
+
+    if builder.options.opt == '1':
+      cxx.cflags += ['-O3']
+
+  def configure_msvc(self, cxx):
+    if builder.options.debug == '1':
+      cxx.cflags += ['/MTd']
+      cxx.linkflags += ['/NODEFAULTLIB:libcmt']
+    else:
+      cxx.cflags += ['/MT']
+    cxx.defines += [
+      '_CRT_SECURE_NO_DEPRECATE',
+      '_CRT_SECURE_NO_WARNINGS',
+      '_CRT_NONSTDC_NO_DEPRECATE',
+      '_ITERATOR_DEBUG_LEVEL=0',
+    ]
+    cxx.cflags += [
+      '/W3',
+    ]
+    cxx.cxxflags += [
+      '/EHsc',
+      '/GR-',
+      '/TP',
+    ]
+    cxx.linkflags += [
+      '/MACHINE:X86',
+      'kernel32.lib',
+      'user32.lib',
+      'gdi32.lib',
+      'winspool.lib',
+      'comdlg32.lib',
+      'advapi32.lib',
+      'shell32.lib',
+      'ole32.lib',
+      'oleaut32.lib',
+      'uuid.lib',
+      'odbc32.lib',
+      'odbccp32.lib',
+    ]
+
+    if builder.options.opt == '1':
+      cxx.cflags += ['/Ox', '/Zo']
+      cxx.linkflags += ['/OPT:ICF', '/OPT:REF']
+
+    if builder.options.debug == '1':
+      cxx.cflags += ['/Od', '/RTC1']
+
+    # This needs to be after our optimization flags which could otherwise disable it.
+    # Don't omit the frame pointer.
+    cxx.cflags += ['/Oy-']
+
+  def configure_linux(self, cxx):
+    cxx.defines += ['_LINUX', 'POSIX']
+    cxx.linkflags += ['-Wl,--exclude-libs,ALL', '-lm']
+    if cxx.vendor == 'gcc':
+      cxx.linkflags += ['-static-libgcc']
+    elif cxx.vendor == 'clang':
+      cxx.linkflags += ['-lgcc_eh']
+
+  def configure_mac(self, cxx):
+    cxx.defines += ['OSX', '_OSX', 'POSIX']
+    cxx.cflags += ['-mmacosx-version-min=10.5']
+    cxx.linkflags += [
+      '-mmacosx-version-min=10.5',
+      '-arch', 'i386',
+      '-lstdc++',
+      '-stdlib=libstdc++',
+    ]
+    cxx.cxxflags += ['-stdlib=libstdc++']
+
+  def configure_windows(self, cxx):
+    cxx.defines += ['WIN32', '_WINDOWS']
+
+  def Program(self, context, name):
+    binary = context.compiler.Program(name)
+    if binary.compiler.like('msvc'):
+      binary.compiler.linkflags.append('/SUBSYSTEM:CONSOLE')
+    return binary
+
+Tool = ProgramConfig()
+Tool.configure()
+
+# Add additional buildscripts here
+BuildScripts = [
+  'AMBuilder',
+]
+
+binary = Tool.Program(builder, 'entlump_parser')
+binary.sources += [
+  'console_main.cpp',
+  os.path.join(builder.options.sm_path, 'core', 'logic', 'LumpManager.cpp'),
+]
+
+binary.compiler.includes += [
+  os.path.join(builder.sourcePath),
+  os.path.join(builder.options.sm_path, 'core', 'logic'),
+]
+
+builder.Add(binary)

tools/entlumpparser/AMBuilder

@@ -0,0 +1,16 @@
+# vim: set sts=2 ts=8 sw=2 tw=99 et ft=python: 
+import os
+
+binary = Tool.Program(builder, 'entlump_parser')
+
+binary.sources += [
+  'console_main.cpp',
+  os.path.join(builder.options.sm_path, 'core', 'logic', 'LumpManager.cpp'),
+]
+
+binary.compiler.includes += [
+  os.path.join(builder.sourcePath),
+  os.path.join(builder.options.sm_path, 'core', 'logic'),
+]
+
+builder.Add(binary)

tools/entlumpparser/configure.py

@@ -0,0 +1,16 @@
+# vim: set sts=2 ts=8 sw=2 tw=99 et:
+import sys
+from ambuild2 import run
+
+# Simple extensions do not need to modify this file.
+
+builder = run.PrepareBuild(sourcePath = sys.path[0])
+
+builder.options.add_option('--sm-path', type=str, dest='sm_path', default=None,
+                       help='Path to SourceMod')
+builder.options.add_option('--enable-debug', action='store_const', const='1', dest='debug',
+                       help='Enable debugging symbols')
+builder.options.add_option('--enable-optimize', action='store_const', const='1', dest='opt',
+                       help='Enable optimization')
+
+builder.Configure()

tools/entlumpparser/console_main.cpp

@@ -0,0 +1,22 @@
+#include <fstream>
+#include <iostream>
+#include <sstream>
+
+#include "LumpManager.h"
+
+int main(int argc, char *argv[]) {
+	if (argc < 2) {
+		std::cout << "Missing input file\n";
+		return 0;
+	}
+
+	const char* filepath = argv[1];
+
+	std::ifstream input(filepath, std::ios_base::binary);
+	std::string data((std::istreambuf_iterator<char>(input)),  std::istreambuf_iterator<char>());
+
+	EntityLumpManager lumpmgr;
+	lumpmgr.Parse(data.c_str());
+
+	std::cout << lumpmgr.Dump() << "\n";
+}