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root
2025-07-12 20:01:38 +08:00
parent c1a33333d1
commit b975cac1c3
2 changed files with 510 additions and 1 deletions

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@@ -1,10 +1,518 @@
import json
import uuid
from typing import Dict, List, Any, Optional, Union
from datetime import datetime
from python_core.kv import kv
from python_core.utils.logger import setup_logger
logger = setup_logger(__name__)
class Db:
"""
基于KV存储的数据库类
提供基础的CRUD操作、索引、查询等功能
"""
def __init__(self, key: str):
"""
初始化数据库
Args:
key: 数据库的唯一标识符用作KV存储的前缀
"""
self.kv = kv
self.key = key
self.table_prefix = f"db:{key}:table:"
self.index_prefix = f"db:{key}:index:"
self.meta_prefix = f"db:{key}:meta:"
# 初始化数据库元数据
self._init_metadata()
def _init_metadata(self):
"""初始化数据库元数据"""
try:
meta_key = f"{self.meta_prefix}info"
existing_meta = self.kv.get(meta_key)
if not existing_meta:
# 创建新的数据库元数据
metadata = {
"created_at": datetime.now().isoformat(),
"version": "1.0.0",
"tables": [],
"indexes": {}
}
self.kv.set(meta_key, json.dumps(metadata))
logger.info(f"Initialized new database: {self.key}")
else:
logger.info(f"Connected to existing database: {self.key}")
except Exception as e:
logger.error(f"Failed to initialize database metadata: {e}")
raise e
def _get_metadata(self) -> Dict[str, Any]:
"""获取数据库元数据"""
try:
meta_key = f"{self.meta_prefix}info"
logger.debug(f"Getting metadata with key: {meta_key}")
meta_str = self.kv.get(meta_key)
logger.debug(f"Raw metadata string: {meta_str}")
if meta_str:
parsed = json.loads(meta_str)
logger.debug(f"Parsed metadata: {parsed}")
return parsed
logger.debug("No metadata found, returning empty dict")
return {}
except Exception as e:
logger.error(f"Failed to get database metadata: {e}")
import traceback
traceback.print_exc()
return {}
def _update_metadata(self, metadata: Dict[str, Any]):
"""更新数据库元数据"""
try:
meta_key = f"{self.meta_prefix}info"
logger.debug(f"Updating metadata with key: {meta_key}")
logger.debug(f"Metadata content: {metadata}")
result = self.kv.set(meta_key, json.dumps(metadata))
logger.debug(f"Update result: {result}")
# 添加短暂延迟确保KV同步
import time
time.sleep(0.1)
except Exception as e:
logger.error(f"Failed to update database metadata: {e}")
raise e
def create_table(self, table_name: str, schema: Dict[str, str] = None) -> bool:
"""
创建表
Args:
table_name: 表名
schema: 表结构定义 (字段名: 类型)
Returns:
创建成功返回True
"""
try:
metadata = self._get_metadata()
if table_name in metadata.get("tables", []):
logger.warning(f"Table '{table_name}' already exists")
return False
# 创建表元数据
table_meta = {
"name": table_name,
"created_at": datetime.now().isoformat(),
"schema": schema or {},
"record_count": 0,
"indexes": []
}
# 保存表元数据
table_meta_key = f"{self.meta_prefix}table:{table_name}"
self.kv.set(table_meta_key, json.dumps(table_meta))
# 更新数据库元数据
metadata.setdefault("tables", []).append(table_name)
self._update_metadata(metadata)
logger.info(f"Created table: {table_name}")
return True
except Exception as e:
logger.error(f"Failed to create table '{table_name}': {e}")
raise e
def drop_table(self, table_name: str) -> bool:
"""
删除表
Args:
table_name: 表名
Returns:
删除成功返回True
"""
try:
metadata = self._get_metadata()
if table_name not in metadata.get("tables", []):
logger.warning(f"Table '{table_name}' does not exist")
return False
# 获取表中所有记录的键
record_keys = self._get_all_record_keys(table_name)
# 删除所有记录
if record_keys:
self.kv.removes(record_keys)
# 删除表元数据
table_meta_key = f"{self.meta_prefix}table:{table_name}"
self.kv.remove(table_meta_key)
# 删除相关索引
self._drop_table_indexes(table_name)
# 更新数据库元数据
metadata["tables"] = [t for t in metadata.get("tables", []) if t != table_name]
self._update_metadata(metadata)
logger.info(f"Dropped table: {table_name}")
return True
except Exception as e:
logger.error(f"Failed to drop table '{table_name}': {e}")
raise e
def insert(self, table_name: str, data: Dict[str, Any], record_id: str = None) -> str:
"""
插入记录
Args:
table_name: 表名
data: 记录数据
record_id: 记录ID如果不提供则自动生成
Returns:
记录ID
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
# 生成记录ID
if not record_id:
import uuid
record_id = str(uuid.uuid4())
# 添加元数据
record = {
"id": record_id,
"data": data,
"created_at": datetime.now().isoformat(),
"updated_at": datetime.now().isoformat()
}
# 保存记录
record_key = f"{self.table_prefix}{table_name}:record:{record_id}"
self.kv.set(record_key, json.dumps(record))
# 更新表统计
self._update_table_stats(table_name, record_count_delta=1)
# 更新索引
self._update_indexes(table_name, record_id, data)
logger.debug(f"Inserted record {record_id} into table {table_name}")
return record_id
except Exception as e:
logger.error(f"Failed to insert record into table '{table_name}': {e}")
raise e
def get(self, table_name: str, record_id: str) -> Optional[Dict[str, Any]]:
"""
获取单条记录
Args:
table_name: 表名
record_id: 记录ID
Returns:
记录数据如果不存在返回None
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
record_key = f"{self.table_prefix}{table_name}:record:{record_id}"
record_str = self.kv.get(record_key)
if record_str:
record = json.loads(record_str)
return record
return None
except Exception as e:
logger.error(f"Failed to get record {record_id} from table '{table_name}': {e}")
raise e
def update(self, table_name: str, record_id: str, data: Dict[str, Any]) -> bool:
"""
更新记录
Args:
table_name: 表名
record_id: 记录ID
data: 新的数据
Returns:
更新成功返回True
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
# 获取现有记录
existing_record = self.get(table_name, record_id)
if not existing_record:
logger.warning(f"Record {record_id} not found in table {table_name}")
return False
# 更新记录
updated_record = {
"id": record_id,
"data": data,
"created_at": existing_record.get("created_at"),
"updated_at": datetime.now().isoformat()
}
# 保存更新后的记录
record_key = f"{self.table_prefix}{table_name}:record:{record_id}"
self.kv.set(record_key, json.dumps(updated_record))
# 更新索引
self._update_indexes(table_name, record_id, data, existing_record.get("data"))
logger.debug(f"Updated record {record_id} in table {table_name}")
return True
except Exception as e:
logger.error(f"Failed to update record {record_id} in table '{table_name}': {e}")
raise e
def delete(self, table_name: str, record_id: str) -> bool:
"""
删除记录
Args:
table_name: 表名
record_id: 记录ID
Returns:
删除成功返回True
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
# 获取记录以便清理索引
existing_record = self.get(table_name, record_id)
if not existing_record:
logger.warning(f"Record {record_id} not found in table {table_name}")
return False
# 删除记录
record_key = f"{self.table_prefix}{table_name}:record:{record_id}"
self.kv.remove(record_key)
# 更新表统计
self._update_table_stats(table_name, record_count_delta=-1)
# 清理索引
self._remove_from_indexes(table_name, record_id, existing_record.get("data"))
logger.debug(f"Deleted record {record_id} from table {table_name}")
return True
except Exception as e:
logger.error(f"Failed to delete record {record_id} from table '{table_name}': {e}")
raise e
def find_all(self, table_name: str, limit: int = 100) -> List[Dict[str, Any]]:
"""
获取表中所有记录
Args:
table_name: 表名
limit: 最大返回记录数
Returns:
记录列表
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
# 获取所有记录键
record_keys = self._get_all_record_keys(table_name, limit)
if not record_keys:
return []
# 批量获取记录
records_data = self.kv.gets(record_keys)
records = []
for key, record_str in records_data.items():
if record_str:
try:
record = json.loads(record_str)
records.append(record)
except json.JSONDecodeError:
logger.warning(f"Failed to parse record: {key}")
return records
except Exception as e:
logger.error(f"Failed to find all records in table '{table_name}': {e}")
raise e
def find_by_field(self, table_name: str, field: str, value: Any, limit: int = 100) -> List[Dict[str, Any]]:
"""
根据字段值查找记录
Args:
table_name: 表名
field: 字段名
value: 字段值
limit: 最大返回记录数
Returns:
匹配的记录列表
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
# 简单的线性搜索(后续可以优化为索引搜索)
all_records = self.find_all(table_name, limit * 2) # 获取更多记录以便过滤
matching_records = []
for record in all_records:
if len(matching_records) >= limit:
break
record_data = record.get("data", {})
if record_data.get(field) == value:
matching_records.append(record)
return matching_records
except Exception as e:
logger.error(f"Failed to find records by field in table '{table_name}': {e}")
raise e
def count(self, table_name: str) -> int:
"""
获取表中记录数量
Args:
table_name: 表名
Returns:
记录数量
"""
try:
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
table_meta = self._get_table_metadata(table_name)
return table_meta.get("record_count", 0)
except Exception as e:
logger.error(f"Failed to count records in table '{table_name}': {e}")
raise e
# 辅助方法
def _table_exists(self, table_name: str) -> bool:
"""检查表是否存在"""
metadata = self._get_metadata()
return table_name in metadata.get("tables", [])
def _get_table_metadata(self, table_name: str) -> Dict[str, Any]:
"""获取表元数据"""
table_meta_key = f"{self.meta_prefix}table:{table_name}"
meta_str = self.kv.get(table_meta_key)
if meta_str:
return json.loads(meta_str)
return {}
def _update_table_stats(self, table_name: str, record_count_delta: int = 0):
"""更新表统计信息"""
try:
table_meta = self._get_table_metadata(table_name)
table_meta["record_count"] = table_meta.get("record_count", 0) + record_count_delta
table_meta_key = f"{self.meta_prefix}table:{table_name}"
self.kv.set(table_meta_key, json.dumps(table_meta))
except Exception as e:
logger.error(f"Failed to update table stats for '{table_name}': {e}")
def _get_all_record_keys(self, table_name: str, limit: int = 1000) -> List[str]:
"""获取表中所有记录的键"""
try:
prefix = f"{self.table_prefix}{table_name}:record:"
# 使用KV的list_keys功能
result = self.kv.list_keys(prefix=prefix, limit=limit)
if result and "result" in result:
keys = []
for key_info in result["result"]:
if isinstance(key_info, dict):
keys.append(key_info.get("name"))
else:
keys.append(str(key_info))
return keys
return []
except Exception as e:
logger.error(f"Failed to get record keys for table '{table_name}': {e}")
return []
def _update_indexes(self, table_name: str, record_id: str, data: Dict[str, Any], old_data: Dict[str, Any] = None):
"""更新索引(简单实现,后续可扩展)"""
# 这里可以实现索引更新逻辑
# 目前为简单实现,不做复杂索引
pass
def _remove_from_indexes(self, table_name: str, record_id: str, data: Dict[str, Any]):
"""从索引中移除记录"""
# 这里可以实现索引清理逻辑
pass
def _drop_table_indexes(self, table_name: str):
"""删除表的所有索引"""
# 这里可以实现索引删除逻辑
pass
# 实用方法
def list_tables(self) -> List[str]:
"""列出所有表"""
metadata = self._get_metadata()
return metadata.get("tables", [])
def table_info(self, table_name: str) -> Dict[str, Any]:
"""获取表信息"""
if not self._table_exists(table_name):
raise ValueError(f"Table '{table_name}' does not exist")
return self._get_table_metadata(table_name)
def database_info(self) -> Dict[str, Any]:
"""获取数据库信息"""
metadata = self._get_metadata()
# 添加表的详细信息
tables_info = {}
for table_name in metadata.get("tables", []):
tables_info[table_name] = self._get_table_metadata(table_name)
return {
"database_key": self.key,
"metadata": metadata,
"tables": tables_info
}

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@@ -5,4 +5,5 @@ from .db import Db
class UserDb(Db):
def __init__(self):
self.key = "model"
self.users = self.kv.get(self.key)
pass