| 1 | """NativeDatabase — ctypes implementation of pywitdb.Database.""" |
| 2 | |
| 3 | from __future__ import annotations |
| 4 | |
| 5 | from collections.abc import Iterator |
| 6 | from contextlib import contextmanager |
| 7 | from ctypes import ( |
| 8 | POINTER, |
| 9 | addressof, |
| 10 | byref, |
| 11 | cast, |
| 12 | c_size_t, |
| 13 | c_uint8, |
| 14 | c_uint32, |
| 15 | create_string_buffer, |
| 16 | string_at, |
| 17 | ) |
| 18 | |
| 19 | from pywitdb._api import Database |
| 20 | from pywitdb._native.lib import ( |
| 21 | WITDB_OK, |
| 22 | WitDbNativeLib, |
| 23 | bytes_to_buf, |
| 24 | load_native_lib, |
| 25 | ) |
| 26 | from pywitdb.exceptions import WitDbStoreError |
| 27 | |
| 28 | |
| 29 | def native_available() -> bool: |
| 30 | return load_native_lib() is not None |
| 31 | |
| 32 | |
| 33 | class NativeDatabase(Database): |
| 34 | def __init__(self, lib: WitDbNativeLib, handle: int, path: str) -> None: |
| 35 | self._lib = lib |
| 36 | self._handle = handle |
| 37 | self._path = path |
| 38 | self._closed = False |
| 39 | |
| 40 | def _check(self, code: int) -> None: |
| 41 | if code == WITDB_OK: |
| 42 | return |
| 43 | msg = "" |
| 44 | try: |
| 45 | raw = self._lib.dll.witdb_last_error_message() |
| 46 | if raw: |
| 47 | msg = raw.decode("utf-8", errors="replace") |
| 48 | except Exception: |
| 49 | pass |
| 50 | raise WitDbStoreError(f"witdb status={code}" + (f": {msg}" if msg else "")) |
| 51 | |
| 52 | def get(self, key: bytes) -> bytes | None: |
| 53 | key_buf, key_len = bytes_to_buf(key) |
| 54 | out_ptr = POINTER(c_uint8)() |
| 55 | out_len = c_uint32() |
| 56 | self._check( |
| 57 | self._lib.dll.witdb_get( |
| 58 | c_size_t(self._handle), |
| 59 | cast(addressof(key_buf), POINTER(c_uint8)), |
| 60 | c_uint32(key_len), |
| 61 | byref(out_ptr), |
| 62 | byref(out_len), |
| 63 | ) |
| 64 | ) |
| 65 | if not out_ptr: |
| 66 | return None |
| 67 | try: |
| 68 | return string_at(out_ptr, out_len.value) |
| 69 | finally: |
| 70 | self._lib.dll.witdb_buffer_free(out_ptr) |
| 71 | |
| 72 | def put(self, key: bytes, value: bytes) -> None: |
| 73 | key_buf, key_len = bytes_to_buf(key) |
| 74 | val_buf, val_len = bytes_to_buf(value) |
| 75 | self._check( |
| 76 | self._lib.dll.witdb_put( |
| 77 | c_size_t(self._handle), |
| 78 | cast(addressof(key_buf), POINTER(c_uint8)), |
| 79 | c_uint32(key_len), |
| 80 | cast(addressof(val_buf), POINTER(c_uint8)), |
| 81 | c_uint32(val_len), |
| 82 | ) |
| 83 | ) |
| 84 | |
| 85 | def delete(self, key: bytes) -> bool: |
| 86 | key_buf, key_len = bytes_to_buf(key) |
| 87 | deleted = c_uint8() |
| 88 | self._check( |
| 89 | self._lib.dll.witdb_delete( |
| 90 | c_size_t(self._handle), |
| 91 | cast(addressof(key_buf), POINTER(c_uint8)), |
| 92 | c_uint32(key_len), |
| 93 | byref(deleted), |
| 94 | ) |
| 95 | ) |
| 96 | return bool(deleted.value) |
| 97 | |
| 98 | @contextmanager |
| 99 | def transaction(self) -> Iterator[None]: |
| 100 | txn_handle = c_size_t() |
| 101 | self._check( |
| 102 | self._lib.dll.witdb_txn_begin(c_size_t(self._handle), byref(txn_handle)) |
| 103 | ) |
| 104 | try: |
| 105 | yield None |
| 106 | self._check(self._lib.dll.witdb_txn_commit(txn_handle)) |
| 107 | except Exception: |
| 108 | self._lib.dll.witdb_txn_rollback(txn_handle) |
| 109 | raise |
| 110 | |
| 111 | def close(self) -> None: |
| 112 | if self._closed: |
| 113 | return |
| 114 | self._closed = True |
| 115 | self._check(self._lib.dll.witdb_close(c_size_t(self._handle))) |
| 116 | |
| 117 | |
| 118 | def open_native( |
| 119 | path: str, |
| 120 | *, |
| 121 | password: str | None = None, |
| 122 | create: bool = True, |
| 123 | ) -> NativeDatabase: |
| 124 | lib = load_native_lib() |
| 125 | if lib is None: |
| 126 | raise WitDbStoreError( |
| 127 | "libwitdb not found; set WITDB_NATIVE_PATH or build OutWit.Database.Native" |
| 128 | ) |
| 129 | |
| 130 | handle = c_size_t() |
| 131 | code = lib.dll.witdb_open( |
| 132 | path.encode("utf-8"), |
| 133 | password.encode("utf-8") if password is not None else None, |
| 134 | c_uint8(1 if create else 0), |
| 135 | byref(handle), |
| 136 | ) |
| 137 | if code != WITDB_OK: |
| 138 | msg = "" |
| 139 | raw = lib.dll.witdb_last_error_message() |
| 140 | if raw: |
| 141 | msg = raw.decode("utf-8", errors="replace") |
| 142 | raise WitDbStoreError(f"witdb_open failed ({code})" + (f": {msg}" if msg else "")) |
| 143 | |
| 144 | return NativeDatabase(lib, int(handle.value), path) |
| 145 | |