使用peewee模型实现持久性的微型同步工具
peewee-syncer的Python项目详细描述
Peewee同步器
使用peewee db模型帮助同步数据以保持状态的小型工具。
可以使用唯一的id记录（如自动插入id）或非唯一记录（如日期/时间戳）
使用is_unique_key=False表示非唯一（请参阅单元测试~）
如果达到限制，offset用于克服“驼峰”（即已在您的表上进行了批量更新）
有关异步支持，请参见（接近尾端）
安装
pip install peewee-syncer
用法
注意下面的示例使用upsert_db_bulk()助手。
这需要sqlite 3.25+来支持upsert*
例如
下载：https://packages.debian.org/search?keywords=libsqlite3-0
sudo dkpk -i libsqlite3-0_3.27.2-2~bpo9+1_amd64.deb
import os
import logging
from functools import partial
from peewee import SqliteDatabase, Model, CharField
from peewee_syncer.utils import upsert_db_bulk
from peewee_syncer import get_sync_manager, SyncManager, Processor, LastOffsetQueryIterator
log = logging.getLogger(__name__)
try:
os.remove('test.db')
except FileNotFoundError:
pass
db = SqliteDatabase('test.db')
SyncManager.init_db(db)
# Run once
SyncManager.create_table()
# A model to sync (could be anything, not peewee specific)
class MyModel(Model):
name = CharField()
# Method to compare/track
@classmethod
def get_key(cls, item):
return item.id
# Method to get records from last offset
@classmethod
def select_since_id(cls, since, limit, offset=None):
q = cls.select().where(cls.id > since)
if limit:
q = q.limit(limit)
return q
class Meta:
database = db
MyModel.create_table()
# Start at zero for first run (otherwise start=None to continue from previous position)
sync_manager = get_sync_manager(app="my-sync-service", start=0)
# A model to sync to (could be anything, not peewee specific)
class MySyncModel(Model):
some_name = CharField()
class Meta:
database = db
# A function to map the output to be synced
def row_output(model):
return {'id': model.id, 'some_name': model.name}
MySyncModel.create_table()
# Iterator Function
def it(since, limit):
q = MyModel.select_since_id(since, limit=limit)
return LastOffsetQueryIterator(q.iterator(),
# Function to convert to output
row_output_fun=row_output,
# Function to check the key of current record we are processing
key_fun=MyModel.get_key,
# The key is unique/atomic (use False if processing time based records as can have many for each key)
is_unique_key=True
)
# Processor
processor = Processor(
sync_manager=sync_manager,
it_function=it,
# A process function (iterates over the iterator)
process_function=partial(upsert_db_bulk, MySyncModel, preserve=['some_name'], conflict_target='id'),
# Pause up to 1 seconds on each iteration (percentage of records vs limit processed)
sleep_duration=1
)
# Add some records
for i in range(25):
MyModel.create(id=i, name="test_{}".format(i))
log.info("MySyncModel has {} records".format(MySyncModel.select().count()))
# Run (batch of ten, five iterations. set i=0 to run forever)
processor.process(limit=10, i=5)
log.info("MySyncModel has {} records".format(MySyncModel.select().count()))
输出
peewee DEBUG ('CREATE TABLE IF NOT EXISTS "sync_manager" ("app" VARCHAR(256) NOT NULL PRIMARY KEY, "meta" TEXT NOT NULL, "modified" DATETIME)', [])
peewee DEBUG ('CREATE TABLE IF NOT EXISTS "mymodel" ("id" INTEGER NOT NULL PRIMARY KEY, "name" VARCHAR(255) NOT NULL)', [])
peewee DEBUG ('SELECT "t1"."app", "t1"."meta", "t1"."modified" FROM "sync_manager" AS "t1" WHERE ("t1"."app" = ?) LIMIT ? OFFSET ?', ['my-sync-service', 1, 0])
peewee DEBUG ('BEGIN', None)
peewee DEBUG ('INSERT INTO "sync_manager" ("app", "meta", "modified") VALUES (?, ?, ?)', ['my-sync-service', '{}', datetime.datetime(2019, 6, 4, 16, 10, 18, 603755)])
peewee DEBUG ('UPDATE "sync_manager" SET "meta" = ?, "modified" = ? WHERE ("sync_manager"."app" = ?)', ['{"value": 0, "type": null, "offset": 0}', datetime.datetime(2019, 6, 4, 16, 10, 18, 609370), 'my-sync-service'])
peewee DEBUG ('CREATE TABLE IF NOT EXISTS "mysyncmodel" ("id" INTEGER NOT NULL PRIMARY KEY, "some_name" VARCHAR(255) NOT NULL)', [])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [0, 'test_0'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [1, 'test_1'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [2, 'test_2'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [3, 'test_3'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [4, 'test_4'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [5, 'test_5'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [6, 'test_6'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [7, 'test_7'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [8, 'test_8'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [9, 'test_9'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [10, 'test_10'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [11, 'test_11'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [12, 'test_12'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [13, 'test_13'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [14, 'test_14'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [15, 'test_15'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [16, 'test_16'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [17, 'test_17'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [18, 'test_18'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [19, 'test_19'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [20, 'test_20'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [21, 'test_21'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [22, 'test_22'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [23, 'test_23'])
peewee DEBUG ('INSERT INTO "mymodel" ("id", "name") VALUES (?, ?)', [24, 'test_24'])
peewee DEBUG ('SELECT COUNT(1) FROM (SELECT 1 FROM "mysyncmodel" AS "t1") AS "_wrapped"', [])
__main__ INFO MySyncModel has 0 records
peewee DEBUG ('SELECT "t1"."id", "t1"."name" FROM "mymodel" AS "t1" WHERE ("t1"."id" > ?) LIMIT ?', [0, 10])
peewee DEBUG ('INSERT INTO "mysyncmodel" ("id", "some_name") VALUES (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?) ON CONFLICT ("id") DO UPDATE SET "some_name" = EXCLUDED."some_name"', [1, 'test_1', 2, 'test_2', 3, 'test_3', 4, 'test_4', 5, 'test_5', 6, 'test_6', 7, 'test_7', 8, 'test_8', 9, 'test_9', 10, 'test_10'])
peewee_syncer DEBUG Processed records n=10 offset=10
peewee DEBUG ('UPDATE "sync_manager" SET "meta" = ?, "modified" = ? WHERE ("sync_manager"."app" = ?)', ['{"value": 10, "type": null, "offset": 0}', datetime.datetime(2019, 6, 4, 16, 10, 18, 837385), 'my-sync-service'])
peewee DEBUG ('SELECT "t1"."id", "t1"."name" FROM "mymodel" AS "t1" WHERE ("t1"."id" > ?) LIMIT ?', [10, 10])
peewee DEBUG ('INSERT INTO "mysyncmodel" ("id", "some_name") VALUES (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?), (?, ?) ON CONFLICT ("id") DO UPDATE SET "some_name" = EXCLUDED."some_name"', [11, 'test_11', 12, 'test_12', 13, 'test_13', 14, 'test_14', 15, 'test_15', 16, 'test_16', 17, 'test_17', 18, 'test_18', 19, 'test_19', 20, 'test_20'])
peewee_syncer DEBUG Processed records n=10 offset=20
peewee DEBUG ('UPDATE "sync_manager" SET "meta" = ?, "modified" = ? WHERE ("sync_manager"."app" = ?)', ['{"value": 20, "type": null, "offset": 0}', datetime.datetime(2019, 6, 4, 16, 10, 18, 855367), 'my-sync-service'])
peewee DEBUG ('SELECT "t1"."id", "t1"."name" FROM "mymodel" AS "t1" WHERE ("t1"."id" > ?) LIMIT ?', [20, 10])
peewee DEBUG ('INSERT INTO "mysyncmodel" ("id", "some_name") VALUES (?, ?), (?, ?), (?, ?), (?, ?) ON CONFLICT ("id") DO UPDATE SET "some_name" = EXCLUDED."some_name"', [21, 'test_21', 22, 'test_22', 23, 'test_23', 24, 'test_24'])
peewee_syncer DEBUG Processed records n=4 offset=24
peewee DEBUG ('UPDATE "sync_manager" SET "meta" = ?, "modified" = ? WHERE ("sync_manager"."app" = ?)', ['{"value": 24, "type": null, "offset": 0}', datetime.datetime(2019, 6, 4, 16, 10, 18, 874314), 'my-sync-service'])
peewee DEBUG ('SELECT "t1"."id", "t1"."name" FROM "mymodel" AS "t1" WHERE ("t1"."id" > ?) LIMIT ?', [24, 10])
peewee_syncer DEBUG Caught up, sleeping..
peewee DEBUG ('SELECT "t1"."id", "t1"."name" FROM "mymodel" AS "t1" WHERE ("t1"."id" > ?) LIMIT ?', [24, 10])
peewee_syncer DEBUG Caught up, sleeping..
peewee_syncer DEBUG Stopping after iteration 5
peewee_syncer INFO Completed processing
peewee DEBUG ('SELECT COUNT(1) FROM (SELECT 1 FROM "mysyncmodel" AS "t1") AS "_wrapped"', [])
__main__ INFO MySyncModel has 24 records
异步
使用peewee async（https://github.com/05bit/peewee-async） 注意：sqlite还不支持：请参见https://github.com/05bit/peewee-async/issues/126
pip install peewee-syncer[async]
或（包括aiopg）
pip install peewee-syncer[async-pg]
或（包括aiomysql）
pip install peewee-syncer[async-mysql]
from peewee_syncer import get_sync_manager, AsyncProcessor
db_object = Manager(db, loop=None)
def it(since=None, limit=None):
log.debug("Getting iterator since={} limit={}".format(since, limit))
def dummy():
for x in range(since+1, since+limit+1):
log.debug("yielded {}".format(x))
yield {"x": x}
return LastOffsetQueryIterator(dummy(), row_output_fun=lambda x:x, key_fun=lambda x:x['x'], is_unique_key=True)
output = []
async def process(it):
nonlocal output
for item in it:
output.append(item)
log.debug("process item: {}".format(item))
processor = AsyncProcessor(
sync_manager=sync_manager,
it_function=it,
process_function=process,
object=db_object
)
async def consume():
await processor.process(limit=10, i=3)
asyncio.get_event_loop().run_until_complete(consume())
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