amf3.c

/*
 * ========================================================================
 * PHP AMF3 encoding/decoding extension
 * Work started by Arseny Vakhrushev on 11 Jan 2010
 * Copyright (C) 2010 IT Territory, LLC. http://it-territory.ru/
 * ========================================================================
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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.
 *
 * Please read the LICENSE file for license details
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <php.h>
#include <Zend/zend_interfaces.h>
#include <ext/standard/info.h>
#include <ext/date/php_date.h>
#include "php_amf3.h"

ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_amf3_encode, 0, 1, IS_STRING, 1)
	ZEND_ARG_INFO(0, value)
ZEND_END_ARG_INFO()

ZEND_BEGIN_ARG_INFO_EX(arginfo_amf3_decode, 0, ZEND_RETURN_VALUE, 1)
	ZEND_ARG_TYPE_INFO(0, data, IS_STRING, 0)
	ZEND_ARG_INFO(1, count)
ZEND_END_ARG_INFO()

static const zend_function_entry amf3_functions[] = {
	ZEND_FE(amf3_encode, arginfo_amf3_encode)
	ZEND_FE(amf3_decode, arginfo_amf3_decode)
	ZEND_FE_END
};

static zend_class_entry *(*sxe_get_element_class_entry)();

static PHP_MINFO_FUNCTION(amf3)
{
	php_info_print_table_start();
	php_info_print_table_header(2, "AMF3 support", "enabled");
	php_info_print_table_row(2, "Version", PHP_AMF3_VERSION);
	php_info_print_table_row(2, "Build Date", __DATE__ " " __TIME__);
	php_info_print_table_row(2, "XML support", sxe_get_element_class_entry ? "enabled" : "disabled");
	php_info_print_table_end();
}

static PHP_MINIT_FUNCTION(amf3)
{
	sxe_get_element_class_entry = (zend_class_entry * (*)())DL_FETCH_SYMBOL(NULL, "sxe_get_element_class_entry");

	return SUCCESS;
}

static const zend_module_dep amf3_deps[] = {
	ZEND_MOD_REQUIRED("date")
	ZEND_MOD_OPTIONAL("SimpleXML")
	ZEND_MOD_END
};

zend_module_entry amf3_module_entry = {
	STANDARD_MODULE_HEADER_EX,
	NULL,
	amf3_deps,
	"amf3",
	amf3_functions,
	PHP_MINIT(amf3),
	NULL,
	NULL,
	NULL,
	PHP_MINFO(amf3),
	PHP_AMF3_VERSION,
	STANDARD_MODULE_PROPERTIES
};

#ifdef COMPILE_DL_AMF3
ZEND_GET_MODULE(amf3)
#endif

/* ============================================================================================================ */

#define AMF3_MAX_INT     268435455 //  (2^28)-1
#define AMF3_MIN_INT    -268435456 // -(2^28)

typedef enum amf3_type_e amf3_type_t;
typedef struct amf3_chunk_s amf3_chunk_t;
typedef struct amf3_env_s amf3_env_t;
typedef struct amf3_traits_s amf3_traits_t;

enum amf3_type_e {
	AMF3_UNDEFINED     = 0x00,
	AMF3_NULL          = 0x01,
	AMF3_FALSE         = 0x02,
	AMF3_TRUE          = 0x03,
	AMF3_INTEGER       = 0x04,
	AMF3_DOUBLE        = 0x05,
	AMF3_STRING        = 0x06,
	AMF3_XMLDOC        = 0x07, // only decoding
	AMF3_DATE          = 0x08,
	AMF3_ARRAY         = 0x09,
	AMF3_OBJECT        = 0x0a, // without externalizable
	AMF3_XML           = 0x0b,
	AMF3_BYTEARRAY     = 0x0c, // only decoding
	AMF3_VECTOR_INT    = 0x0d, // no support
	AMF3_VECTOR_UINT   = 0x0e, // no support
	AMF3_VECTOR_DOUBLE = 0x0f, // no support
	AMF3_VECTOR_OBJECT = 0x10, // no support
	AMF3_DICTIONARY    = 0x11, // no support
};

struct amf3_chunk_s {
	char             buf[1000]; // some suitable chunk size to store both small and big buffers well enough and to fit 1Kb memory block
	int              size;
	amf3_chunk_t     *next;
};

struct amf3_env_s {
	HashTable        strs;
	HashTable        objs;
	HashTable        traits;
};

struct amf3_traits_s {
	zend_class_entry *ce;
	int              memberCount;
	char             **members;
	int              *memberLengths;
	int              dynamic;
};

static int amf3_encodeVal(amf3_chunk_t **chunk, zval *val, amf3_env_t *env);
static int amf3_decodeVal(zval *val, const char *data, int pos, int size, amf3_env_t *env);

/* ============================================================================================================ */


static amf3_chunk_t *amf3_initChunk() {
	amf3_chunk_t *chunk;

	chunk = (amf3_chunk_t *)ecalloc(1, sizeof(*chunk));
	if (!chunk) {
		return NULL;
	}
	return chunk;
}

static amf3_chunk_t *amf3_appendChunk(amf3_chunk_t *chunk, const char *buf, int size) {
	if (!chunk) {
		return NULL;
	}
	for ( ;; ) {
		int avail = sizeof(chunk->buf) - chunk->size;
		if (avail >= size) {
			break;
		}
		memcpy(chunk->buf + chunk->size, buf, avail);
		chunk->size += avail;
		buf += avail;
		size -= avail;
		if (!chunk->next) {
			chunk->next = amf3_initChunk();
		}
		chunk = chunk->next;
	}
	memcpy(chunk->buf + chunk->size, buf, size);
	chunk->size += size;
	return chunk;
}

static void amf3_freeChunk(amf3_chunk_t *chunk, char *buf) {
	amf3_chunk_t *next;
	while (chunk) {
		next = chunk->next;
		memcpy(buf, chunk->buf, chunk->size);
		buf += chunk->size;
		efree(chunk);
		chunk = next;
	}
}

static int amf3_getStrIdx(amf3_env_t *env, const char *str, int len) {
	if (len <= 0) {
		return -1; // empty string is never sent by reference
	}
	if (len > AMF3_MAX_INT) {
		len = AMF3_MAX_INT;
	}
	zval *oldIdx;
	if ((oldIdx = zend_hash_str_find(&env->strs, str, len)) != NULL) {
		return Z_LVAL_P(oldIdx);
	}
	int newIdx = zend_hash_num_elements(&env->strs);
	if (newIdx <= AMF3_MAX_INT) {
		zval tmp;
		ZVAL_LONG(&tmp, newIdx);
		zend_hash_str_add(&env->strs, str, len, &tmp);
	}
	return -1;
}

static int amf3_getObjIdx(amf3_env_t *env, zval *val) {
	void *key = NULL;
	if (Z_TYPE_P(val) == IS_ARRAY) {
		key = Z_ARR_P(val);
	} else if (Z_TYPE_P(val) == IS_OBJECT) {
		key = Z_OBJ_P(val);
	}

	zval *oldIdx;
	if ((oldIdx = zend_hash_str_find(&env->objs, (char *)&key, sizeof(key))) != NULL) {
		return Z_LVAL_P(oldIdx);
	}
	int newIdx = zend_hash_num_elements(&env->objs);
	if (newIdx <= AMF3_MAX_INT) {
		zval tmp;
		ZVAL_LONG(&tmp, newIdx);
		zend_hash_str_add(&env->objs, (char *)&key, sizeof(key), &tmp);
	}
	return -1;
}

static int amf3_getTraitsIdx(amf3_env_t *env, zend_class_entry *ce) {
	zval *oldIdx;
	if ((oldIdx = zend_hash_str_find(&env->traits, (char *)&ce, sizeof(ce))) != NULL) {
		return Z_LVAL_P(oldIdx);
	}
	int newIdx = zend_hash_num_elements(&env->traits);
	if (newIdx <= AMF3_MAX_INT) {
		zval tmp;
		ZVAL_LONG(&tmp, newIdx);
		zend_hash_str_add(&env->traits, (char *)&ce, sizeof(ce), &tmp);
	}
	return -1;
}

static zval *amf3_getRef(HashTable *ht, int idx) {
	zval *val;
	if ((val = zend_hash_index_find(ht, idx)) != NULL) {
		Z_TRY_ADDREF_P(val);
		return val;
	}
	return NULL;
}

static void amf3_putRef(HashTable *ht, zval *val) {
	Z_TRY_ADDREF_P(val);
	zend_hash_index_update(ht, zend_hash_num_elements(ht), val);
}


/* ============================================================================================================ */


static int amf3_encodeChar(amf3_chunk_t **chunk, char c) {
	*chunk = amf3_appendChunk(*chunk, &c, 1);
	return 1;
}

static int amf3_encodeU29(amf3_chunk_t **chunk, int val) {
	char buf[4];
	int pos;
	val &= 0x1fffffff;
	if (val <= 0x7f) {
		buf[0] = val;
		pos = 1;
	} else if (val <= 0x3fff) {
		buf[1] = val & 0x7f;
		val >>= 7;
		buf[0] = val | 0x80;
		pos = 2;
	} else if (val <= 0x1fffff) {
		buf[2] = val & 0x7f;
		val >>= 7;
		buf[1] = val | 0x80;
		val >>= 7;
		buf[0] = val | 0x80;
		pos = 3;
	} else {
		buf[3] = val;
		val >>= 8;
		buf[2] = val | 0x80;
		val >>= 7;
		buf[1] = val | 0x80;
		val >>= 7;
		buf[0] = val | 0x80;
		pos = 4;
	}
	*chunk = amf3_appendChunk(*chunk, buf, pos);
	return pos;
}

static int amf3_decodeU29(int *val, const char *buf, int size) {
	int pos = 0, res = 0, tmp;
	do {
		if (pos >= size) {
			return -1;
		}
		tmp = buf[pos];
		if (pos == 3) {
			res <<= 8;
			res |= tmp & 0xff;
		} else {
			res <<= 7;
			res |= tmp & 0x7f;
		}
	} while ((++pos < 4) && (tmp & 0x80));
	*val = res;
	return pos;
}

static int amf3_encodeDouble(amf3_chunk_t **chunk, double val) {
	union {
		double d;
		uint64_t l;
	} u = { val };
	uint64_t l = u.l;
	char buf[8];
	int i;
	for (i = 0; i < 8; ++i) {
		buf[7 - i] = l;
		l >>= 8;
	}
	*chunk = amf3_appendChunk(*chunk, buf, 8);
	return 8;
}

static int amf3_decodeDouble(double *val, const char *buf, int size) {
	if (size < 8) {
		return -1;
	}
	uint64_t l = 0;
	int i;
	for (i = 0; i < 8; ++i) {
		l <<= 8;
		l |= buf[i] & 0xff;
	}
	union {
		uint64_t l;
		double d;
	} u = { l };
	*val = u.d;
	return 8;
}

static int amf3_encodeStr(amf3_chunk_t **chunk, const char *str, int len, amf3_env_t *env) {
	int pos = 0, idx = amf3_getStrIdx(env, str, len);
	if (idx >= 0) {
		pos += amf3_encodeU29(chunk, idx << 1); // encode as a reference
	} else {
		if (len > AMF3_MAX_INT) {
			len = AMF3_MAX_INT;
		}
		pos += amf3_encodeU29(chunk, (len << 1) | 1) + len;
		*chunk = amf3_appendChunk(*chunk, str, len);
	}
	return pos;
}

static int amf3_decodeStr(const char **str, unsigned int *len, const char *buf, int size, amf3_env_t *env) {
	int pfx, pos = amf3_decodeU29(&pfx, buf, size);
	if (pos < 0) {
		return -1;
	}
	if (!(pfx & 1)) { // decode as a reference
		zval *val;
		if ((val = zend_hash_index_find(&env->strs, pfx >> 1)) == NULL) {
			return -1;
		}
		*str = Z_STRVAL_P(val);
		*len = Z_STRLEN_P(val);
	} else {
		pfx >>= 1;
		if ((pfx < 0) || ((pos + pfx) > size)) {
			return -1;
		}
		*str = buf + pos;
		*len = pfx;
		if (pfx > 0) { // empty string is never sent by reference
			zval val;
			ZVAL_STRINGL(&val, buf + pos, pfx);
			zend_hash_index_update(&env->strs, zend_hash_num_elements(&env->strs), &val);
		}
		pos += pfx;
	}
	return pos;
}

static int amf3_encodeDate(amf3_chunk_t **chunk, zval *val, amf3_env_t *env) {
	int pos = amf3_encodeChar(chunk, AMF3_DATE);
	int idx = amf3_getObjIdx(env, val);
	if (idx >= 0) {
		pos += amf3_encodeU29(chunk, idx << 1); // encode as a reference
	} else {
		zval return_value;
		double date;

#if PHP_VERSION_ID >= 80000
		zend_call_method_with_0_params(Z_OBJ_P(val), NULL, NULL, "gettimestamp", &return_value);
#else
		zend_call_method_with_0_params(val, NULL, NULL, "gettimestamp", &return_value);
#endif

		pos += amf3_encodeU29(chunk, 1);
		date = Z_LVAL(return_value);
		pos += amf3_encodeDouble(chunk, date * 1000.0);
	}
	return pos;
}

static int amf3_encodeArray(amf3_chunk_t **chunk, zval *val, amf3_env_t *env) {
	int pos = amf3_encodeChar(chunk, AMF3_ARRAY);
	int idx = amf3_getObjIdx(env, val);
	if (idx >= 0) {
		pos += amf3_encodeU29(chunk, idx << 1); // encode as a reference
	} else {
		HashTable *ht = Z_ARRVAL_P(val);
		zval *hv;
		char keyBuf[22];
		zend_string *key;
		ulong num = 0;
		uint keyLen;
		ulong idx;

		ZEND_HASH_FOREACH_KEY(ht, idx, key) {
			if (key || idx != num) {
				break;
			}
			++num;
		} ZEND_HASH_FOREACH_END();
		if (num == zend_hash_num_elements(ht)) { // sequence of values with integer indexes starting from zero
			if (num > AMF3_MAX_INT) {
				num = AMF3_MAX_INT;
			}
			pos += amf3_encodeU29(chunk, (num << 1) | 1); // dense part size
			pos += amf3_encodeChar(chunk, 0x01); // end of associative part
			ZEND_HASH_FOREACH_VAL(ht, hv) {
				pos += amf3_encodeVal(chunk, hv, env);
			} ZEND_HASH_FOREACH_END();
		} else { // associative array with mixed keys
			pos += amf3_encodeChar(chunk, 0x01); // empty dense part
			ZEND_HASH_FOREACH_KEY_VAL(ht, idx, key, hv) {
				if (key) {
					if (key->len == 0) {
						continue; // empty keys can't be represented in AMF3
					}
					pos += amf3_encodeStr(chunk, key->val, key->len, env);
				} else {
					keyLen = sprintf(keyBuf, "%ld", idx);
					pos += amf3_encodeStr(chunk, keyBuf, keyLen, env);
				}
				pos += amf3_encodeVal(chunk, hv, env);
			} ZEND_HASH_FOREACH_END();
			pos += amf3_encodeChar(chunk, 0x01); // end of associative part
		}
	}
	return pos;
}

static int amf3_encodeXml(amf3_chunk_t **chunk, zval *val, amf3_env_t *env) {
	int pos = amf3_encodeChar(chunk, AMF3_XML);
	int idx = amf3_getObjIdx(env, val);
	if (idx >= 0) {
		pos += amf3_encodeU29(chunk, idx << 1); // encode as a reference
	} else {
		zval xml;
		int xmlLen;

#if PHP_VERSION_ID >= 80000
		zend_call_method_with_0_params(Z_OBJ_P(val), NULL, NULL, "asxml", &xml);
#else
		zend_call_method_with_0_params(val, NULL, NULL, "asxml", &xml);
#endif

		xmlLen = Z_STRLEN(xml);
		if (xmlLen > AMF3_MAX_INT) {
			xmlLen = AMF3_MAX_INT;
		}
		pos += amf3_encodeU29(chunk, (xmlLen << 1) | 1);
		*chunk = amf3_appendChunk(*chunk, Z_STRVAL(xml), xmlLen);
		pos += xmlLen;

		zend_string_release(Z_STR(xml));
	}
	return pos;
}

static int amf3_encodeObjectTraits(amf3_chunk_t **chunk, zval *val, zend_class_entry *ce, amf3_env_t *env) {
	int pos = 0;
	int idx = amf3_getTraitsIdx(env, ce);
	if (idx >= 0) {
		pos += amf3_encodeU29(chunk, (idx << 2) | 1); // encode as a reference
	} else {
		if (ce == zend_standard_class_def) {
			pos += amf3_encodeU29(chunk, 0x0b);
			pos += amf3_encodeChar(chunk, 0x01); // empty class name
		} else {
			HashTable *ht = Z_OBJPROP_P(val);
			zend_string *key;
			int members = 0;

			// count number of properties
			ZEND_HASH_FOREACH_STR_KEY(ht, key) {
				if (key) {
					if (key->len == 0 || key->val[0] == 0) {
						continue; // skip empty key and private/protected properties
					}
					if (!zend_hash_exists(&ce->properties_info, key)) {
						continue; // skip dynamic properties
					}
					members++;
				}
			} ZEND_HASH_FOREACH_END();

			pos += amf3_encodeU29(chunk, (members << 4) | 0x0b);
			pos += amf3_encodeStr(chunk, ce->name->val, ce->name->len, env);

			// write property names
			ZEND_HASH_FOREACH_STR_KEY(ht, key) {
				if (key) {
					if (key->len == 0 || key->val[0] == 0) {
						continue; // skip empty key and private/protected properties
					}
					if (!zend_hash_exists(&ce->properties_info, key)) {
						continue; // skip dynamic properties
					}
					pos += amf3_encodeStr(chunk, key->val, key->len, env);
				}
			} ZEND_HASH_FOREACH_END();
		}
	}

	return pos;
}

static int amf3_encodeObject(amf3_chunk_t **chunk, zval *val, amf3_env_t *env) {
	int pos = 0, idx;
	zend_class_entry *ce = Z_OBJCE_P(val);

	if (instanceof_function(ce, php_date_get_date_ce())) {
		pos += amf3_encodeDate(chunk, val, env);
		return pos;
	} else if (instanceof_function(ce, php_date_get_immutable_ce())) {
		pos += amf3_encodeDate(chunk, val, env);
		return pos;
	} else if (sxe_get_element_class_entry && instanceof_function(ce, sxe_get_element_class_entry())) {
		pos += amf3_encodeXml(chunk, val, env);
		return pos;
	}

	pos = amf3_encodeChar(chunk, AMF3_OBJECT);
	idx = amf3_getObjIdx(env, val);
	if (idx >= 0) {
		pos += amf3_encodeU29(chunk, idx << 1); // encode as a reference
	} else {
		HashTable *ht = Z_OBJPROP_P(val);
		zval *hv;
		char keyBuf[22];
		zend_string *key;
		uint keyLen;
		ulong idx;

		pos += amf3_encodeObjectTraits(chunk, val, ce, env);
		if (ce == zend_standard_class_def) { // encode as dynamic anonymous object
			ZEND_HASH_FOREACH_KEY_VAL(ht, idx, key, hv) {
				if (key) {
					if (key->len == 0 || key->val[0] == 0) {
						continue; // skip empty key and private/protected properties
					}
					pos += amf3_encodeStr(chunk, key->val, key->len, env);
					pos += amf3_encodeVal(chunk, hv, env);
				} else {
					// arrays with integer indexes when cast to object produce
					// objects with integer property names
					keyLen = sprintf(keyBuf, "%ld", idx);
					pos += amf3_encodeStr(chunk, keyBuf, keyLen, env);
					pos += amf3_encodeVal(chunk, hv, env);
				}
			} ZEND_HASH_FOREACH_END();

			pos += amf3_encodeChar(chunk, 0x01); // end of dynamic members
		} else { // encode as typed object
			// write property values
			ZEND_HASH_FOREACH_STR_KEY_VAL(ht, key, hv) {
				if (key) {
					if (key->len == 0 || key->val[0] == 0) {
						continue; // skip empty key and private/protected properties
					}
					if (!zend_hash_exists(&ce->properties_info, key)) {
						continue; // skip dynamic properties
					}
					pos += amf3_encodeVal(chunk, hv, env);
				}
			} ZEND_HASH_FOREACH_END();

			ZEND_HASH_FOREACH_STR_KEY_VAL(ht, key, hv) {
				if (key) {
					if (key->len == 0 || key->val[0] == 0) {
						continue; // skip empty key and private/protected properties
					}
					if (zend_hash_exists(&ce->properties_info, key)) {
						continue;
					}
					pos += amf3_encodeStr(chunk, key->val, key->len, env);
					pos += amf3_encodeVal(chunk, hv, env);
				}
			} ZEND_HASH_FOREACH_END();

			pos += amf3_encodeChar(chunk, 0x01); // end of dynamic members
		}
	}
	return pos;
}

static int amf3_encodeVal(amf3_chunk_t **chunk, zval *val, amf3_env_t *env) {
	int pos = 0;
	switch (Z_TYPE_P(val)) {
		case IS_NULL:
			pos += amf3_encodeChar(chunk, AMF3_NULL);
			break;
		case IS_TRUE:
			pos += amf3_encodeChar(chunk, AMF3_TRUE);
			break;
		case IS_FALSE:
			pos += amf3_encodeChar(chunk, AMF3_FALSE);
			break;
		case IS_LONG:
			if ((Z_LVAL_P(val) < AMF3_MIN_INT) || (Z_LVAL_P(val) > AMF3_MAX_INT)) {
				pos += amf3_encodeChar(chunk, AMF3_DOUBLE);
				pos += amf3_encodeDouble(chunk, Z_LVAL_P(val));
			} else {
				pos += amf3_encodeChar(chunk, AMF3_INTEGER);
				pos += amf3_encodeU29(chunk, Z_LVAL_P(val));
			}
			break;
		case IS_DOUBLE:
			pos += amf3_encodeChar(chunk, AMF3_DOUBLE);
			pos += amf3_encodeDouble(chunk, Z_DVAL_P(val));
			break;
		case IS_STRING:
			pos += amf3_encodeChar(chunk, AMF3_STRING);
			pos += amf3_encodeStr(chunk, Z_STRVAL_P(val), Z_STRLEN_P(val), env);
			break;
		case IS_ARRAY:
			pos += amf3_encodeArray(chunk, val, env);
			break;
		case IS_OBJECT:
			pos += amf3_encodeObject(chunk, val, env);
			break;
		case IS_REFERENCE:
			pos += amf3_encodeVal(chunk, Z_REFVAL_P(val), env);
			break;
		case IS_INDIRECT:
			pos += amf3_encodeVal(chunk, Z_INDIRECT_P(val), env);
			break;
		default:
			php_error_docref(NULL, E_WARNING, "Unable to encode unsupported value type %d", Z_TYPE_P(val));
			break;
	}
	return pos;
}

static int amf3_decodeArray(zval *val, const char *data, int pos, int size, amf3_env_t *env) {
	int oldPos = pos;
	int pfx, res = amf3_decodeU29(&pfx, data + pos, size - pos);
	if (res < 0) {
		php_error_docref(NULL, E_WARNING, "Can't decode array prefix at position %d", pos);
		return -1;
	}
	pos += res;
	if (!(pfx & 1)) { // decode as a reference
		zval *tmp = amf3_getRef(&env->objs, pfx >> 1);
		if (!tmp) {
			php_error_docref(NULL, E_WARNING, "Missing array reference index at position %d", pos - res);
			return -1;
		}
		*val = *tmp;
	} else {
		pfx >>= 1;
		if ((pfx < 0) || ((pos + pfx) > size)) {
			php_error_docref(NULL, E_WARNING, "Invalid dense array portion size at position %d", pos - res);
			return -1;
		}
		array_init(val);
		HT_ALLOW_COW_VIOLATION(Z_ARRVAL_P(val));
		amf3_putRef(&env->objs, val);
		const char *key;
		unsigned int keyLen;
		zval hv;
		for ( ;; ) { // associative array portion
			res = amf3_decodeStr(&key, &keyLen, data + pos, size - pos, env);
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode array key at position %d", pos);
				return -1;
			}
			pos += res;
			if (!keyLen) {
				break;
			}

			res = amf3_decodeVal(&hv, data, pos, size, env);
			if (res > 0) { // need a trailing \0 in the key buffer to do a proper call to 'add_assoc_zval_ex'
#if PHP_VERSION_ID >= 70400
				HT_ALLOW_COW_VIOLATION(Z_ARRVAL_P(val));
#endif
				add_assoc_zval_ex(val, key, keyLen, &hv);
			} else {
				return -1; // nested error
			}
			pos += res;
		}
		while (pfx-- > 0) {
			res = amf3_decodeVal(&hv, data, pos, size, env);
			if (res > 0) {
#if PHP_VERSION_ID >= 70400
				HT_ALLOW_COW_VIOLATION(Z_ARRVAL_P(val));
#endif
				add_next_index_zval(val, &hv);
			} else {
				return -1; // nested error
			}
			pos += res;
		}
	}
	return pos - oldPos;
}

static int amf3_decodeObject(zval *val, const char *data, int pos, int size, amf3_env_t *env) {
	int oldPos = pos;
	int pfx, res = amf3_decodeU29(&pfx, data + pos, size - pos);
	if (res < 0) {
		php_error_docref(NULL, E_WARNING, "Can't decode object prefix at position %d", pos);
		return -1;
	}
	pos += res;
	if (!(pfx & 1)) { // decode as a reference
		zval *tmp = amf3_getRef(&env->objs, pfx >> 1);
		if (!tmp) {
			php_error_docref(NULL, E_WARNING, "Missing object reference index at position %d", pos - res);
			return -1;
		}
		*val = *tmp;
	} else {
		amf3_traits_t *traits;
		int members;
		const char *key;
		unsigned int keyLen;
		zval prop;

		if (!(pfx & 2)) { // decode traits as a reference
			ulong idx = pfx >> 2;
			zval *found;
			if ((found = zend_hash_index_find(&env->traits, idx)) == NULL) {
				php_error_docref(NULL, E_WARNING, "Missing object traits reference index at position %d", pos - res);
				return -1;
			}

			traits = (amf3_traits_t *)Z_PTR_P(found);
		} else {
			if (pfx & 4) {
				php_error_docref(NULL, E_WARNING, "Can't decode externalizable object at position %d", pos);
				return -1;
			}

			members = pfx >> 4;
			if ((members < 0) || ((pos + members) > size)) {
				php_error_docref(NULL, E_WARNING, "Invalid number of class members at position %d", pos - res);
				return -1;
			}

			res = amf3_decodeStr(&key, &keyLen, data + pos, size - pos, env); // class name
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode class name at position %d", pos);
				return -1;
			}
			if (members > 0 && !keyLen) {
				php_error_docref(NULL, E_WARNING, "Empty class name at position %d", pos);
				return -1;
			}
			pos += res;

			traits = (amf3_traits_t *)ecalloc(1, sizeof(*traits));
			zval tmp;
			ZVAL_PTR(&tmp, traits);
			zend_hash_index_update(&env->traits, zend_hash_num_elements(&env->traits), &tmp);

			if (keyLen) {
				// do not try to autoload class, autoloading based on user supplied data is a bad idea
				zend_string *str = zend_string_init(key, keyLen, 0);
				traits->ce = zend_fetch_class(str, ZEND_FETCH_CLASS_NO_AUTOLOAD);
				zend_string_release(str);
				if (traits->ce == NULL) {
					php_error_docref(NULL, E_WARNING, "Unable to find class at position %d", pos - res);
					return -1;
				}
			}

			traits->memberCount = members;
			if (members > 0) {
				traits->members = (char **)ecalloc(traits->memberCount, sizeof(*traits->members));
				traits->memberLengths = (int *)ecalloc(traits->memberCount, sizeof(*traits->memberLengths));
				for (members = 0; members < traits->memberCount; members++) {
					res = amf3_decodeStr(&key, &keyLen, data + pos, size - pos, env); // member names
					if (res < 0) {
						return -1; // nested error
					}
					if (!keyLen || key[0] == 0) {
						php_error_docref(NULL, E_WARNING, "Invalid member name at position %d", pos);
						return -1;
					}

					if (!zend_hash_str_exists(&traits->ce->properties_info, key, keyLen)) {
						php_error_docref(NULL, E_WARNING, "Unknown member name at position %d", pos);
						return -1;
					}

					pos += res;

					traits->members[members] = estrndup(key, keyLen);
					traits->memberLengths[members] = keyLen;
				}
			}

			traits->dynamic = pfx & 0x08;
		}

		if (traits->ce) {
			object_init_ex(val, traits->ce);
		} else {
			object_init(val);
		}
		amf3_putRef(&env->objs, val);

		for (members = 0; members < traits->memberCount; members++) { // sealed members
			res = amf3_decodeVal(&prop, data, pos, size, env);
			if (res > 0) {
				add_property_zval_ex(val, traits->members[members], traits->memberLengths[members], &prop);
				Z_TRY_DELREF_P(&prop);
			} else {
				return -1; // nested error
			}
			pos += res;
		}

		if (traits->dynamic) { // dynamic members
			for ( ;; ) {
				res = amf3_decodeStr(&key, &keyLen, data + pos, size - pos, env);
				if (res < 0) {
					php_error_docref(NULL, E_WARNING, "Can't decode dynamic member name at position %d", pos);
					return -1;
				}
				pos += res;
				if (!keyLen) {
					break;
				}
				if (key[0] == 0) {
					php_error_docref(NULL, E_WARNING, "Invalid dynamic property name at position %d", pos - res);
					return -1;
				}

				if (traits->ce) {
					if (zend_hash_str_exists(&traits->ce->properties_info, key, keyLen)) {
						php_error_docref(NULL, E_WARNING, "Invalid dynamic property name at position %d", pos - res);
						return -1;
					}
				}

				res = amf3_decodeVal(&prop, data, pos, size, env);
				if (res > 0) { // need a trailing \0 in the key buffer to do a proper call to 'add_property_zval_ex'
					add_property_zval_ex(val, key, keyLen, &prop);
					Z_TRY_DELREF_P(&prop);
				} else {
					return -1; // nested error
				}
				pos += res;
			}
		}
	}
	return pos - oldPos;
}

static int amf3_decodeXml(zval *val, const char *data, int pos, int size, amf3_env_t *env) {
	int oldPos = pos;
	int pfx, res = amf3_decodeU29(&pfx, data + pos, size - pos);
	if (res < 0) {
		php_error_docref(NULL, E_WARNING, "Can't decode XML prefix at position %d", pos);
		return -1;
	}
	pos += res;
	if (!(pfx & 1)) { // decode as a reference
		zval *tmp = amf3_getRef(&env->objs, pfx >> 1);
		if (!tmp) {
			php_error_docref(NULL, E_WARNING, "Missing XML reference index at position %d", pos - res);
			return -1;
		}
		*val = *tmp;
	} else {
		zval simplexml_load_string, xml;

		pfx >>= 1;
		if ((pfx < 0) || ((pos + pfx) > size)) {
			php_error_docref(NULL, E_WARNING, "Can't decode XML at position %d", pos);
			return -1;
		}

		ZVAL_STRINGL(&simplexml_load_string, "simplexml_load_string", sizeof("simplexml_load_string") - 1);

		ZVAL_STRINGL(&xml, data + pos, pfx);
		if (call_user_function(EG(function_table), NULL, &simplexml_load_string, val, 1, &xml) == FAILURE ||
			(Z_TYPE_P(val) == IS_FALSE)) {
			zend_string_release(Z_STR(simplexml_load_string));
			zend_string_release(Z_STR(xml));
			php_error_docref(NULL, E_WARNING, "Can't load XML at position %d", pos);
			return -1;
		}

		amf3_putRef(&env->objs, val);
		pos += pfx;

		zend_string_release(Z_STR(simplexml_load_string));
		zend_string_release(Z_STR(xml));
	}
	return pos - oldPos;
}

static int amf3_decodeVal(zval *val, const char *data, int pos, int size, amf3_env_t *env) {
	if ((pos < 0) || (pos >= size)) {
		php_error_docref(NULL, E_WARNING, "Can't decode type specifier at position %d", pos);
		return -1;
	}
	int oldPos = pos;
	amf3_type_t type = (uint8_t)data[pos++];
	switch (type) {
		case AMF3_UNDEFINED:
		case AMF3_NULL:
			ZVAL_NULL(val);
			break;
		case AMF3_FALSE:
			ZVAL_FALSE(val);
			break;
		case AMF3_TRUE:
			ZVAL_TRUE(val);
			break;
		case AMF3_INTEGER: {
			int i;
			int res = amf3_decodeU29(&i, data + pos, size - pos);
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode integer at position %d", pos);
				return -1;
			}
			if (i & 0x10000000) {
				i |= ~0x1fffffff; // prolong sign bits if negative
			}
			ZVAL_LONG(val, i);
			pos += res;
			break;
		}
		case AMF3_DOUBLE: {
			double d;
			int res = amf3_decodeDouble(&d, data + pos, size - pos);
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode double at position %d", pos);
				return -1;
			}
			ZVAL_DOUBLE(val, d);
			pos += res;
			break;
		}
		case AMF3_STRING: {
			int pfx, res = amf3_decodeU29(&pfx, data + pos, size - pos);
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode string prefix at position %d", pos);
				return -1;
			}
			pos += res;
			if (!(pfx & 1)) { // decode as a reference
				zval *tmp = amf3_getRef(&env->strs, pfx >> 1);
				if (!tmp) {
					php_error_docref(NULL, E_WARNING, "Missing string reference index at position %d", pos - res);
					return -1;
				}
				*val = *tmp;
			} else {
				pfx >>= 1;
				if ((pfx < 0) || ((pos + pfx) > size)) {
					php_error_docref(NULL, E_WARNING, "Invalid string length at position %d", pos - res);
					return -1;
				}
				ZVAL_STRINGL(val, data + pos, pfx);
				pos += pfx;
				if (pfx > 0) {
					amf3_putRef(&env->strs, val); // empty string is never sent by reference
				}
			}
			break;
		}
		case AMF3_DATE: {
			int pfx, res = amf3_decodeU29(&pfx, data + pos, size - pos);
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode date prefix at position %d", pos);
				return -1;
			}
			pos += res;
			if (!(pfx & 1)) { // decode as a reference
				zval *tmp = amf3_getRef(&env->objs, pfx >> 1);
				if (!tmp) {
					php_error_docref(NULL, E_WARNING, "Missing date reference index at position %d", pos - res);
					return -1;
				}
				*val = *tmp;
			} else {
				double d;
				char buf[64];
				int bufLen;
				res = amf3_decodeDouble(&d, data + pos, size - pos);
				if (res < 0 || d < 0.0) {
					php_error_docref(NULL, E_WARNING, "Can't decode date at position %d", pos);
					return -1;
				}

				bufLen = snprintf(buf, sizeof(buf), "%.0f", d/1000.0);
				php_date_instantiate(php_date_get_date_ce(), val);
				if (!php_date_initialize(Z_PHPDATE_P(val), buf, bufLen, "U", NULL, 0)) {
					php_error_docref(NULL, E_WARNING, "Can't initialize date at position %d", pos);
					return -1;
				}

				amf3_putRef(&env->objs, val);
				pos += res;
			}
			break;
		}
		case AMF3_ARRAY: {
			int res = amf3_decodeArray(val, data, pos, size, env);
			if (res < 0) {
				return -1; // nested error
			}
			pos += res;
			break;
		}
		case AMF3_OBJECT: {
			int res = amf3_decodeObject(val, data, pos, size, env);
			if (res < 0) {
				return -1; // nested error
			}
			pos += res;
			break;
		}
		case AMF3_XMLDOC:
		case AMF3_XML: {
			int res = amf3_decodeXml(val, data, pos, size, env);
			if (res < 0) {
				return -1; // nested error
			}
			pos += res;
			break;
		}
		case AMF3_BYTEARRAY: {
			int pfx, res = amf3_decodeU29(&pfx, data + pos, size - pos);
			if (res < 0) {
				php_error_docref(NULL, E_WARNING, "Can't decode byte array prefix at position %d", pos);
				return -1;
			}
			pos += res;
			if (!(pfx & 1)) { // decode as a reference
				zval *tmp = amf3_getRef(&env->objs, pfx >> 1);
				if (!tmp) {
					php_error_docref(NULL, E_WARNING, "Missing byte array reference index at position %d", pos - res);
					return -1;
				}
				*val = *tmp;
			} else {
				pfx >>= 1;
				if ((pfx < 0) || ((pos + pfx) > size)) {
					php_error_docref(NULL, E_WARNING, "Invalid byte array length at position %d", pos - res);
					return -1;
				}
				ZVAL_STRINGL(val, data + pos, pfx);
				pos += pfx;
				amf3_putRef(&env->objs, val);
			}
			break;
		}
		default:
			php_error_docref(NULL, E_WARNING, "Unsupported value type 0x%02X at position %d", type, pos - 1);
			return -1;
	}
	return pos - oldPos;
}

static void traits_ptr_dtor(zval *val) {
	int i;
	amf3_traits_t *traits = (amf3_traits_t *)Z_PTR_P(val);
	if (traits->members) {
		for (i = 0; i < traits->memberCount; i++) {
			if (traits->members[i]) {
				efree(traits->members[i]);
			}
		}
		efree(traits->members);
	}
	if (traits->memberLengths) {
		efree(traits->memberLengths);
	}
	efree(traits);
}

static void amf3_initEnv(amf3_env_t *env, int dtor) {
	memset(env, 0, sizeof(*env));
	zend_hash_init(&env->strs, 10, NULL, dtor ? ZVAL_PTR_DTOR : NULL, 0);
	zend_hash_init(&env->objs, 10, NULL, dtor ? ZVAL_PTR_DTOR : NULL, 0);
	zend_hash_init(&env->traits, 10, NULL, dtor ? traits_ptr_dtor : NULL, 0);
}

static void amf3_destroyEnv(amf3_env_t *env) {
	zend_hash_destroy(&env->strs);
	zend_hash_destroy(&env->objs);
	zend_hash_destroy(&env->traits);
}


/* ============================================================================================================ */


/* {{{ proto string amf3_encode(mixed value)
   Encodes given value into AMF3 */
PHP_FUNCTION(amf3_encode) {
	zval *val;
	if (zend_parse_parameters(ZEND_NUM_ARGS(), "z", &val) == FAILURE) {
		RETURN_FALSE;
	}
	amf3_chunk_t *begin = amf3_initChunk();
	amf3_chunk_t *current = begin;
	amf3_env_t env;

	amf3_initEnv(&env, 0);
	int size = amf3_encodeVal(&current, val, &env);
	amf3_destroyEnv(&env);

	char *buf = (char *)emalloc(size);
	amf3_freeChunk(begin, buf);
	RETVAL_STRINGL(buf, size);
	efree(buf);
}
/* }}} */

/* {{{ proto mixed amf3_decode(string data [, int &count])
   Decodes given AMF3 data to PHP type */
PHP_FUNCTION(amf3_decode) {
	char *data;
	size_t size;
	zval *count = NULL;
	if (zend_parse_parameters(ZEND_NUM_ARGS(), "s|z/", &data, &size, &count) == FAILURE) {
		RETURN_FALSE;
	}
	amf3_env_t env;
	amf3_initEnv(&env, 1);
	int res = amf3_decodeVal(return_value, data, 0, size, &env);
	amf3_destroyEnv(&env);
	if (count) {
		zval_dtor(count);
		ZVAL_LONG(count, res);
	}
	if (res < 0) {
		Z_TRY_DELREF_P(return_value);
		RETURN_NULL();
	}
}
/* }}} */