Source code for accounting.storage.ledgercli

# Part of accounting-api project:
# https://gitorious.org/conservancy/accounting-api
# License: AGPLv3-or-later

import sys
import subprocess
import logging
import time
import re

from datetime import datetime
from xml.etree import ElementTree
from contextlib import contextmanager

from accounting.exceptions import AccountingException, TransactionNotFound
from accounting.models import Account, Transaction, Posting, Amount
from accounting.storage import Storage

_log = logging.getLogger(__name__)


[docs]class Ledger(Storage): def __init__(self, app=None, ledger_file=None, ledger_bin=None): if app: ledger_file = app.config['LEDGER_FILE'] if ledger_file is None: raise ValueError('ledger_file cannot be None') self.ledger_bin = ledger_bin or 'ledger' self.ledger_file = ledger_file _log.info('ledger file: %s', ledger_file) self.locked = False self.ledger_process = None @contextmanager
[docs] def locked_process(self): r''' Context manager that checks that the ledger process is not already locked, then "locks" the process and yields the process handle and unlocks the process when execution is returned. Since this decorated as a :func:`contextlib.contextmanager` the recommended use is with the ``with``-statement. .. code-block:: python with self.locked_process() as p: p.stdin.write(b'bal\n') output = self.read_until_prompt(p) ''' if self.locked: raise RuntimeError('The process has already been locked,' ' something\'s out of order.') # XXX: This code has no purpose in a single-threaded process timeout = 5 # Seconds for i in range(1, timeout + 2): if i > timeout: raise RuntimeError('Ledger process is already locked') if not self.locked: break else: _log.info('Waiting for one second... %d/%d', i, timeout) time.sleep(1) process = self.get_process() self.locked = True _log.debug('Lock enabled') yield process self.locked = False _log.debug('Lock disabled')
[docs] def assemble_arguments(self): ''' Returns a list of arguments suitable for :class:`subprocess.Popen` based on :attr:`self.ledger_bin` and :attr:`self.ledger_file`. ''' return [ self.ledger_bin, '-f', self.ledger_file, ]
[docs] def init_process(self): ''' Creates a new (presumably) ledger subprocess based on the args from :meth:`Ledger.assemble_arguments()` and then runs :meth:`Ledger.read_until_prompt()` once (which should return the banner text) and discards the output. ''' _log.debug('Starting ledger process...') self.ledger_process = subprocess.Popen( self.assemble_arguments(), stdout=subprocess.PIPE, stdin=subprocess.PIPE, stderr=subprocess.PIPE) # Swallow the banner with self.locked_process() as p: self.read_until_prompt(p) return self.ledger_process
[docs] def get_process(self): ''' Returns :attr:`self.ledger_process` if it evaluates to ``True``. If :attr:`self.ledger_process` is not set the result of :meth:`self.init_process() <Ledger.init_process>` is returned. ''' return self.ledger_process or self.init_process()
[docs] def read_until_prompt(self, process): r''' Reads from the subprocess instance :data:`process` until it finds a combination of ``\n]\x20`` (the prompt), then returns the output without the prompt. ''' output = b'' while True: line = process.stdout.read(1) # XXX: This is a hack if len(line) > 0: pass #_log.debug('line: %s', line) output += line if b'\n] ' in output: _log.debug('Found prompt!') break output = output[:-3] # Cut away the prompt _log.debug('output: %s', output) return output
[docs] def send_command(self, command): output = None with self.locked_process() as p: if isinstance(command, str): command = command.encode('utf8') _log.debug('Sending command: %r', command) p.stdin.write(command + b'\n') p.stdin.flush() output = self.read_until_prompt(p) self.ledger_process.send_signal(subprocess.signal.SIGTERM) _log.debug('Waiting for ledger to shut down') self.ledger_process.wait() self.ledger_process = None return output
[docs] def add_transaction(self, transaction): ''' Writes a transaction to the ledger file by opening it in 'ab' mode and writing a ledger transaction based on the :class:`~accounting.models.Transaction` instance in :data:`transaction`. ''' if transaction.id is None: _log.debug('No ID found. Generating an ID.') transaction.generate_id() transaction.metadata.update({'Id': transaction.id}) transaction_template = ('\n{date} {t.payee}\n' '{metadata}' '{postings}') metadata_template = ' ;{0}: {1}\n' # TODO: Generate metadata for postings posting_template = (' {account} {p.amount.symbol}' ' {p.amount.amount}\n') output = b'' # XXX: Even I hardly understands what this does, however I indent it it # stays unreadable. output += transaction_template.format( date=transaction.date.strftime('%Y-%m-%d'), t=transaction, metadata=''.join([ metadata_template.format(k, v) for k, v in transaction.metadata.items()]), postings=''.join([posting_template.format( p=p, account=p.account + ' ' * ( 80 - (len(p.account) + len(p.amount.symbol) + len(str(p.amount.amount)) + 1 + 2) )) for p in transaction.postings ]) ).encode('utf8') with open(self.ledger_file, 'ab') as f: f.write(output) _log.info('Added transaction %s', transaction.id) _log.debug('written to file: %s', output) return transaction.id
[docs] def bal(self): output = self.send_command('xml') if output is None: raise RuntimeError('bal call returned no output') accounts = [] xml = ElementTree.fromstring(output.decode('utf8')) accounts = self._recurse_accounts(xml.find('./accounts')) return accounts
def _recurse_accounts(self, root): accounts = [] for account in root.findall('./account'): name = account.find('./fullname').text amounts = [] # Try to find an account total value, then try to find the account # balance account_amounts = account.findall( './account-total/balance/amount') or \ account.findall('./account-amount/amount') or \ account.findall('./account-total/amount') if account_amounts: for amount in account_amounts: quantity = amount.find('./quantity').text symbol = amount.find('./commodity/symbol').text amounts.append(Amount(amount=quantity, symbol=symbol)) else: _log.warning('Account %s does not have any amounts', name) accounts.append(Account(name=name, amounts=amounts, accounts=self._recurse_accounts(account))) return accounts
[docs] def get_transactions(self): return self.reg()
[docs] def get_transaction(self, transaction_id): transactions = self.get_transactions() for transaction in transactions: if transaction.id == transaction_id: return transaction raise TransactionNotFound( 'No transaction with id {0} found'.format(transaction_id))
[docs] def reg(self): output = self.send_command('xml') if output is None: raise RuntimeError('reg call returned no output') entries = [] reg_xml = ElementTree.fromstring(output.decode('utf8')) for transaction in reg_xml.findall('./transactions/transaction'): date = datetime.strptime(transaction.find('./date').text, '%Y/%m/%d') payee = transaction.find('./payee').text postings = [] for posting in transaction.findall('./postings/posting'): account = posting.find('./account/name').text amount = posting.find('./post-amount/amount/quantity').text symbol = posting.find( './post-amount/amount/commodity/symbol').text # Get the posting metadata metadata = {} values = posting.findall('./metadata/value') if values: for value in values: key = value.get('key') value = value.find('./string').text _log.debug('metadata: %s: %s', key, value) metadata.update({key: value}) postings.append( Posting(account=account, metadata=metadata, amount=Amount(amount=amount, symbol=symbol))) # Get the transaction metadata metadata = {} values = transaction.findall('./metadata/value') if values: for value in values: key = value.get('key') value = value.find('./string').text _log.debug('metadata: %s: %s', key, value) metadata.update({key: value}) # Add a Transaction instance to the list try: id = metadata.pop('Id') except KeyError: _log.warning('Transaction on %s with payee %s does not have an' ' Id attribute. A temporary ID will be used.', date, payee) id = 'NO-ID' entries.append( Transaction(id=id, date=date, payee=payee, postings=postings, metadata=metadata)) return entries
[docs] def delete_transaction(self, transaction_id): ''' Delete a transaction from the ledger file. This method opens the ledger file, loads all lines into memory and looks for the transaction_id, then looks for the bounds of that transaction in the ledger file, removes all lines within the bounds of the transaction and removes them, then writes the lines back to the ledger file. Exceptions: - RuntimeError: If all boundaries to the transaction are not found - TransactionNotFound: If no such transaction_id can be found in :data:`self.ledger_file` ''' f = open(self.ledger_file, 'r') lines = [i for i in f] # A mapping of line meanings and their line numbers as found by the # following logic semantic_lines = dict( id_location=None, transaction_start=None, next_transaction_or_eof=None ) for i, line in enumerate(lines): if transaction_id in line: semantic_lines['id_location'] = i break if not semantic_lines['id_location']: raise TransactionNotFound( 'No transaction with ID "{0}" found'.format(transaction_id)) transaction_start_pattern = re.compile(r'^\S') cursor = semantic_lines['id_location'] - 1 # Find the first line of the transaction while True: if transaction_start_pattern.match(lines[cursor]): semantic_lines['transaction_start'] = cursor break cursor -= 1 cursor = semantic_lines['id_location'] + 1 # Find the last line of the transaction while True: try: if transaction_start_pattern.match(lines[cursor]): semantic_lines['next_transaction_or_eof'] = cursor break except IndexError: # Set next_line_without_starting_space_or_end_of_file to # the cursor. The cursor will be an index not included in the # list of lines semantic_lines['next_transaction_or_eof'] = cursor break cursor += 1 if not all(map(lambda v: v is not None, semantic_lines.values())): raise RuntimeError('Could not find all the values necessary for' ' safe deletion of a transaction.') del_start = semantic_lines['transaction_start'] if len(lines) == semantic_lines['next_transaction_or_eof']: _log.debug('There are no transactions below the transaction being' ' deleted. The line before the first line of the' ' transaction will be deleted.') # Delete the preceding line to make the file del_start -= 1 _log.info('Removing transaction with ID: %s (lines %d-%d)', transaction_id, del_start, semantic_lines['next_transaction_or_eof']) del lines[del_start:semantic_lines['next_transaction_or_eof']] with open(self.ledger_file, 'w') as f: for line in lines: f.write(line)
[docs] def update_transaction(self, transaction): ''' Update a transaction in the ledger file. Takes a :class:`~accounting.models.Transaction` object and removes the old transaction using :data:`transaction.id` from the passed :class:`~accounting.models.Transaction` instance and adds :data:`transaction` to the database. ''' if not transaction.id: return AccountingException(('The transaction {0} has no' ' id attribute').format(transaction)) old_transaction = self.get_transaction(transaction.id) self.delete_transaction(transaction.id) self.add_transaction(transaction) _log.info('Updated transaction %s', transaction.id) _log.debug('Updated transaction from: %s to: %s', old_transaction, transaction)
[docs]def main(argv=None): import argparse if argv is None: argv = sys.argv parser = argparse.ArgumentParser() parser.add_argument('-v', '--verbosity', default='INFO', help=('Filter logging output. Possible values:' + ' CRITICAL, ERROR, WARNING, INFO, DEBUG')) args = parser.parse_args(argv[1:]) logging.basicConfig(level=getattr(logging, args.verbosity, 'INFO')) ledger = Ledger(ledger_file='non-profit-test-data.ledger') print(ledger.bal()) print(ledger.reg())
if __name__ == '__main__': sys.exit(main())

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