import sqlite3
import time

COMMIT_TIME=2 # s

class DB:
	def __init__(self,filename):
		self.filename=filename
		self.connection=sqlite3.connect(self.filename)
		self.connection.row_factory=sqlite3.Row
		self.commitTime=time.time()

	def setup(self):
		# !! err if exists
		self.connection.execute("""create table `hashes` (
			`sector_id` integer primary key,
			`sector_hash` blob not null,
			`updated` integer
		)""")

		self.connection.commit()

	## Inserts hash into the DB.
	#
	# @param sectorHash bytes object containing the hash
	def insertHash(self,sectorId,sectorHash):
		# !! if not connection
		res=self.connection.execute("""insert or replace into `hashes` (`sector_id`, `sector_hash`, `updated`)
			values (?, ?, strftime('%s','now'))""", (sectorId,sectorHash))
		t=time.time()
		if t-self.commitTime > COMMIT_TIME:
			self.connection.commit()
			self.commitTime=t
		return res

	def listHashes(self):
		# !! if not connection
		return self.connection.execute("""select * from `hashes` order by `sector_id` asc""")