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py-bedrock/bedrock/leveldb.py
2020-06-06 03:27:05 -04:00

219 lines
10 KiB
Python

# Provides an python wrapper for the ctypes wrapper for the c wrapper for leveldb.
import ctypes
import os.path as op
import sys
if sys.platform == "win32":
if sys.maxsize > 2**32: # 64 bit python
ldb = ctypes.cdll.LoadLibrary(op.join(op.dirname(op.realpath(__file__)), "LevelDB-MCPE-64.dll"))
else: # 32 bit python
ldb = ctypes.cdll.LoadLibrary(op.join(op.dirname(op.realpath(__file__)), "LevelDB-MCPE-32.dll"))
else: #linux, compile your own .so if this errors!
ldb = ctypes.cdll.LoadLibrary(op.join(op.dirname(op.realpath(__file__)), "libleveldb.so")) # Load DLL
# Setup ctypes arguments and return types for all of the leveldb functions.
# Most of this pulled from Podshot/MCEdit-Unified
ldb.leveldb_filterpolicy_create_bloom.argtypes = [ctypes.c_int]
ldb.leveldb_filterpolicy_create_bloom.restype = ctypes.c_void_p
ldb.leveldb_filterpolicy_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_filterpolicy_destroy.restype = None
ldb.leveldb_cache_create_lru.argtypes = [ctypes.c_size_t]
ldb.leveldb_cache_create_lru.restype = ctypes.c_void_p
ldb.leveldb_cache_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_cache_destroy.restype = None
ldb.leveldb_options_create.argtypes = []
ldb.leveldb_options_create.restype = ctypes.c_void_p
ldb.leveldb_options_set_filter_policy.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_options_set_filter_policy.restype = None
ldb.leveldb_options_set_create_if_missing.argtypes = [ctypes.c_void_p, ctypes.c_ubyte]
ldb.leveldb_options_set_create_if_missing.restype = None
ldb.leveldb_options_set_error_if_exists.argtypes = [ctypes.c_void_p, ctypes.c_ubyte]
ldb.leveldb_options_set_error_if_exists.restype = None
ldb.leveldb_options_set_paranoid_checks.argtypes = [ctypes.c_void_p, ctypes.c_ubyte]
ldb.leveldb_options_set_paranoid_checks.restype = None
ldb.leveldb_options_set_write_buffer_size.argtypes = [ctypes.c_void_p, ctypes.c_size_t]
ldb.leveldb_options_set_write_buffer_size.restype = None
ldb.leveldb_options_set_max_open_files.argtypes = [ctypes.c_void_p, ctypes.c_int]
ldb.leveldb_options_set_max_open_files.restype = None
ldb.leveldb_options_set_cache.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_options_set_cache.restype = None
ldb.leveldb_options_set_block_size.argtypes = [ctypes.c_void_p, ctypes.c_size_t]
ldb.leveldb_options_set_block_size.restype = None
ldb.leveldb_options_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_options_destroy.restype = None
ldb.leveldb_options_set_compression.argtypes = [ctypes.c_void_p, ctypes.c_int]
ldb.leveldb_options_set_compression.restype = None
ldb.leveldb_open.argtypes = [ctypes.c_void_p, ctypes.c_char_p, ctypes.c_void_p]
ldb.leveldb_open.restype = ctypes.c_void_p
ldb.leveldb_close.argtypes = [ctypes.c_void_p]
ldb.leveldb_close.restype = None
ldb.leveldb_put.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t, ctypes.c_void_p, ctypes.c_size_t, ctypes.c_void_p]
ldb.leveldb_put.restype = None
ldb.leveldb_delete.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t, ctypes.c_void_p]
ldb.leveldb_delete.restype = None
ldb.leveldb_write.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_write.restype = None
ldb.leveldb_get.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t, ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_get.restype = ctypes.POINTER(ctypes.c_char)
ldb.leveldb_writeoptions_create.argtypes = []
ldb.leveldb_writeoptions_create.restype = ctypes.c_void_p
ldb.leveldb_writeoptions_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_writeoptions_destroy.restype = None
ldb.leveldb_writeoptions_set_sync.argtypes = [ctypes.c_void_p, ctypes.c_ubyte]
ldb.leveldb_writeoptions_set_sync.restype = None
ldb.leveldb_readoptions_create.argtypes = []
ldb.leveldb_readoptions_create.restype = ctypes.c_void_p
ldb.leveldb_readoptions_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_readoptions_destroy.restype = None
ldb.leveldb_readoptions_set_verify_checksums.argtypes = [ctypes.c_void_p, ctypes.c_ubyte]
ldb.leveldb_readoptions_set_verify_checksums.restype = None
ldb.leveldb_readoptions_set_fill_cache.argtypes = [ctypes.c_void_p, ctypes.c_ubyte]
ldb.leveldb_readoptions_set_fill_cache.restype = None
ldb.leveldb_readoptions_set_snapshot.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_readoptions_set_snapshot.restype = None
ldb.leveldb_create_iterator.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_create_iterator.restype = ctypes.c_void_p
ldb.leveldb_iter_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_iter_destroy.restype = None
ldb.leveldb_iter_valid.argtypes = [ctypes.c_void_p]
ldb.leveldb_iter_valid.restype = ctypes.c_bool
ldb.leveldb_iter_key.argtypes = [ctypes.c_void_p, ctypes.POINTER(ctypes.c_size_t)]
ldb.leveldb_iter_key.restype = ctypes.c_void_p
ldb.leveldb_iter_value.argtypes = [ctypes.c_void_p, ctypes.POINTER(ctypes.c_size_t)]
ldb.leveldb_iter_value.restype = ctypes.c_void_p
ldb.leveldb_iter_next.argtypes = [ctypes.c_void_p]
ldb.leveldb_iter_next.restype = None
ldb.leveldb_iter_prev.argtypes = [ctypes.c_void_p]
ldb.leveldb_iter_prev.restype = None
ldb.leveldb_iter_seek_to_first.argtypes = [ctypes.c_void_p]
ldb.leveldb_iter_seek_to_first.restype = None
ldb.leveldb_iter_seek_to_last.argtypes = [ctypes.c_void_p]
ldb.leveldb_iter_seek_to_last.restype = None
ldb.leveldb_iter_seek.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t]
ldb.leveldb_iter_seek.restype = None
ldb.leveldb_iter_get_error.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_iter_get_error.restype = None
ldb.leveldb_writebatch_create.argtypes = []
ldb.leveldb_writebatch_create.restype = ctypes.c_void_p
ldb.leveldb_writebatch_destroy.argtypes = [ctypes.c_void_p]
ldb.leveldb_writebatch_destroy.restype = None
ldb.leveldb_writebatch_clear.argtypes = [ctypes.c_void_p]
ldb.leveldb_writebatch_clear.restype = None
ldb.leveldb_writebatch_put.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t, ctypes.c_void_p, ctypes.c_size_t]
ldb.leveldb_writebatch_put.restype = None
ldb.leveldb_writebatch_delete.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t]
ldb.leveldb_writebatch_delete.restype = None
ldb.leveldb_approximate_sizes.argtypes = [ctypes.c_void_p, ctypes.c_int, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_approximate_sizes.restype = None
ldb.leveldb_compact_range.argtypes = [ctypes.c_void_p, ctypes.c_void_p, ctypes.c_size_t, ctypes.c_void_p, ctypes.c_size_t]
ldb.leveldb_compact_range.restype = None
ldb.leveldb_create_snapshot.argtypes = [ctypes.c_void_p]
ldb.leveldb_create_snapshot.restype = ctypes.c_void_p
ldb.leveldb_release_snapshot.argtypes = [ctypes.c_void_p, ctypes.c_void_p]
ldb.leveldb_release_snapshot.restype = None
ldb.leveldb_free.argtypes = [ctypes.c_void_p]
ldb.leveldb_free.restype = None
# Utility function for checking the error code returned by some leveldb functions.
def _checkError(err):
if bool(err): # Not an empty null-terminated string
message = ctypes.string_at(err)
ldb.leveldb_free(ctypes.cast(err, ctypes.c_void_p))
raise Exception(message)
def open(path):
# Bloom filter: an efficient way to tell if something is in a cache.
filter_policy = ldb.leveldb_filterpolicy_create_bloom(10)
cache = ldb.leveldb_cache_create_lru(40 * 1024 * 1024)
options = ldb.leveldb_options_create()
# Many of these options were pulled from Podshot/MCEdit-Unified
ldb.leveldb_options_set_compression(options, 4)
ldb.leveldb_options_set_filter_policy(options, filter_policy)
ldb.leveldb_options_set_create_if_missing(options, False)
ldb.leveldb_options_set_write_buffer_size(options, 4 * 1024 * 1024)
ldb.leveldb_options_set_cache(options, cache)
ldb.leveldb_options_set_block_size(options, 163840)
error = ctypes.POINTER(ctypes.c_char)()
db = ldb.leveldb_open(options, path.encode("utf-8"), ctypes.byref(error))
ldb.leveldb_options_destroy(options)
_checkError(error)
return db
def get(db, key):
ro = ldb.leveldb_readoptions_create()
size = ctypes.c_size_t(0)
error = ctypes.POINTER(ctypes.c_char)()
valPtr = ldb.leveldb_get(db, ro, key, len(key), ctypes.byref(size), ctypes.byref(error))
ldb.leveldb_readoptions_destroy(ro)
_checkError(error)
if bool(valPtr):
val = ctypes.string_at(valPtr, size.value)
ldb.leveldb_free(ctypes.cast(valPtr, ctypes.c_void_p))
else:
raise KeyError("Key {} not found in database.".format(key))
return val
def put(db, key, val):
wo = ldb.leveldb_writeoptions_create()
error = ctypes.POINTER(ctypes.c_char)()
ldb.leveldb_put(db, wo, key, len(key), val, len(val), ctypes.byref(error))
ldb.leveldb_writeoptions_destroy(wo)
_checkError(error)
def putBatch(db, data):
batch = ldb.leveldb_writebatch_create()
for k, v in data.items():
ldb.leveldb_writebatch_put(batch, k, len(k), v, len(v))
wo = ldb.leveldb_writeoptions_create()
error = ctypes.POINTER(ctypes.c_char)()
ldb.leveldb_write(db, wo, batch, ctypes.byref(error))
ldb.leveldb_writeoptions_destroy(wo)
_checkError(error)
def delete(db, key):
wo = ldb.leveldb_writeoptions_create()
error = ctypes.POINTER(ctypes.c_char)()
ldb.leveldb_delete(db, wo, key, len(key), ctypes.byref(error))
ldb.leveldb_writeoptions_destroy(wo)
_checkError(error)
def iterate(db, start=None, end=None):
ro = ldb.leveldb_readoptions_create()
it = ldb.leveldb_create_iterator(db, ro)
ldb.leveldb_readoptions_destroy(ro)
if start is None:
ldb.leveldb_iter_seek_to_first(it)
else:
ldb.leveldb_iter_seek(it, start, len(start))
try:
while ldb.leveldb_iter_valid(it):
size = ctypes.c_size_t(0)
keyPtr = ldb.leveldb_iter_key(it, ctypes.byref(size))
key = ctypes.string_at(keyPtr, size.value)
if end is not None and key >= end:
break
valPtr = ldb.leveldb_iter_value(it, ctypes.byref(size))
val = ctypes.string_at(valPtr, size.value)
yield key, val
ldb.leveldb_iter_next(it)
finally:
ldb.leveldb_iter_destroy(it)
def close(db):
ldb.leveldb_close(db)