1 | #-----------------------------------------------------------------------
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2 | #
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3 | # Copyright (C) 2000, 2001 by Autonomous Zone Industries
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4 | # Copyright (C) 2002 Gregory P. Smith
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5 | #
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6 | # License: This is free software. You may use this software for any
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7 | # purpose including modification/redistribution, so long as
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8 | # this header remains intact and that you do not claim any
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9 | # rights of ownership or authorship of this software. This
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10 | # software has been tested, but no warranty is expressed or
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11 | # implied.
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12 | #
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13 | # -- Gregory P. Smith <greg@krypto.org>
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14 |
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15 | # This provides a simple database table interface built on top of
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16 | # the Python Berkeley DB 3 interface.
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17 | #
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18 | _cvsid = '$Id: dbtables.py 66088 2008-08-31 14:00:51Z jesus.cea $'
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19 |
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20 | import re
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21 | import sys
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22 | import copy
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23 | import random
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24 | import struct
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25 | import cPickle as pickle
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26 |
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27 | try:
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28 | # For Pythons w/distutils pybsddb
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29 | from bsddb3 import db
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30 | except ImportError:
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31 | # For Python 2.3
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32 | from bsddb import db
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33 |
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34 | # XXX(nnorwitz): is this correct? DBIncompleteError is conditional in _bsddb.c
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35 | if not hasattr(db,"DBIncompleteError") :
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36 | class DBIncompleteError(Exception):
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37 | pass
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38 | db.DBIncompleteError = DBIncompleteError
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39 |
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40 | class TableDBError(StandardError):
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41 | pass
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42 | class TableAlreadyExists(TableDBError):
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43 | pass
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44 |
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45 |
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46 | class Cond:
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47 | """This condition matches everything"""
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48 | def __call__(self, s):
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49 | return 1
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50 |
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51 | class ExactCond(Cond):
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52 | """Acts as an exact match condition function"""
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53 | def __init__(self, strtomatch):
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54 | self.strtomatch = strtomatch
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55 | def __call__(self, s):
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56 | return s == self.strtomatch
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57 |
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58 | class PrefixCond(Cond):
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59 | """Acts as a condition function for matching a string prefix"""
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60 | def __init__(self, prefix):
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61 | self.prefix = prefix
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62 | def __call__(self, s):
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63 | return s[:len(self.prefix)] == self.prefix
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64 |
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65 | class PostfixCond(Cond):
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66 | """Acts as a condition function for matching a string postfix"""
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67 | def __init__(self, postfix):
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68 | self.postfix = postfix
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69 | def __call__(self, s):
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70 | return s[-len(self.postfix):] == self.postfix
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71 |
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72 | class LikeCond(Cond):
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73 | """
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74 | Acts as a function that will match using an SQL 'LIKE' style
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75 | string. Case insensitive and % signs are wild cards.
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76 | This isn't perfect but it should work for the simple common cases.
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77 | """
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78 | def __init__(self, likestr, re_flags=re.IGNORECASE):
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79 | # escape python re characters
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80 | chars_to_escape = '.*+()[]?'
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81 | for char in chars_to_escape :
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82 | likestr = likestr.replace(char, '\\'+char)
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83 | # convert %s to wildcards
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84 | self.likestr = likestr.replace('%', '.*')
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85 | self.re = re.compile('^'+self.likestr+'$', re_flags)
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86 | def __call__(self, s):
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87 | return self.re.match(s)
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88 |
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89 | #
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90 | # keys used to store database metadata
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91 | #
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92 | _table_names_key = '__TABLE_NAMES__' # list of the tables in this db
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93 | _columns = '._COLUMNS__' # table_name+this key contains a list of columns
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94 |
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95 | def _columns_key(table):
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96 | return table + _columns
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97 |
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98 | #
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99 | # these keys are found within table sub databases
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100 | #
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101 | _data = '._DATA_.' # this+column+this+rowid key contains table data
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102 | _rowid = '._ROWID_.' # this+rowid+this key contains a unique entry for each
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103 | # row in the table. (no data is stored)
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104 | _rowid_str_len = 8 # length in bytes of the unique rowid strings
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105 |
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106 |
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107 | def _data_key(table, col, rowid):
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108 | return table + _data + col + _data + rowid
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109 |
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110 | def _search_col_data_key(table, col):
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111 | return table + _data + col + _data
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112 |
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113 | def _search_all_data_key(table):
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114 | return table + _data
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115 |
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116 | def _rowid_key(table, rowid):
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117 | return table + _rowid + rowid + _rowid
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118 |
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119 | def _search_rowid_key(table):
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120 | return table + _rowid
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121 |
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122 | def contains_metastrings(s) :
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123 | """Verify that the given string does not contain any
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124 | metadata strings that might interfere with dbtables database operation.
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125 | """
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126 | if (s.find(_table_names_key) >= 0 or
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127 | s.find(_columns) >= 0 or
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128 | s.find(_data) >= 0 or
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129 | s.find(_rowid) >= 0):
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130 | # Then
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131 | return 1
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132 | else:
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133 | return 0
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134 |
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135 |
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136 | class bsdTableDB :
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137 | def __init__(self, filename, dbhome, create=0, truncate=0, mode=0600,
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138 | recover=0, dbflags=0):
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139 | """bsdTableDB(filename, dbhome, create=0, truncate=0, mode=0600)
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140 |
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141 | Open database name in the dbhome Berkeley DB directory.
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142 | Use keyword arguments when calling this constructor.
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143 | """
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144 | self.db = None
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145 | myflags = db.DB_THREAD
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146 | if create:
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147 | myflags |= db.DB_CREATE
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148 | flagsforenv = (db.DB_INIT_MPOOL | db.DB_INIT_LOCK | db.DB_INIT_LOG |
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149 | db.DB_INIT_TXN | dbflags)
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150 | # DB_AUTO_COMMIT isn't a valid flag for env.open()
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151 | try:
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152 | dbflags |= db.DB_AUTO_COMMIT
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153 | except AttributeError:
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154 | pass
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155 | if recover:
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156 | flagsforenv = flagsforenv | db.DB_RECOVER
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157 | self.env = db.DBEnv()
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158 | # enable auto deadlock avoidance
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159 | self.env.set_lk_detect(db.DB_LOCK_DEFAULT)
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160 | self.env.open(dbhome, myflags | flagsforenv)
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161 | if truncate:
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162 | myflags |= db.DB_TRUNCATE
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163 | self.db = db.DB(self.env)
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164 | # this code relies on DBCursor.set* methods to raise exceptions
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165 | # rather than returning None
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166 | self.db.set_get_returns_none(1)
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167 | # allow duplicate entries [warning: be careful w/ metadata]
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168 | self.db.set_flags(db.DB_DUP)
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169 | self.db.open(filename, db.DB_BTREE, dbflags | myflags, mode)
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170 | self.dbfilename = filename
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171 |
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172 | if sys.version_info[0] >= 3 :
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173 | class cursor_py3k(object) :
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174 | def __init__(self, dbcursor) :
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175 | self._dbcursor = dbcursor
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176 |
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177 | def close(self) :
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178 | return self._dbcursor.close()
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179 |
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180 | def set_range(self, search) :
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181 | v = self._dbcursor.set_range(bytes(search, "iso8859-1"))
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182 | if v != None :
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183 | v = (v[0].decode("iso8859-1"),
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184 | v[1].decode("iso8859-1"))
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185 | return v
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186 |
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187 | def __next__(self) :
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188 | v = getattr(self._dbcursor, "next")()
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189 | if v != None :
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190 | v = (v[0].decode("iso8859-1"),
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191 | v[1].decode("iso8859-1"))
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192 | return v
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193 |
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194 | class db_py3k(object) :
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195 | def __init__(self, db) :
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196 | self._db = db
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197 |
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198 | def cursor(self, txn=None) :
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199 | return cursor_py3k(self._db.cursor(txn=txn))
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200 |
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201 | def has_key(self, key, txn=None) :
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202 | return getattr(self._db,"has_key")(bytes(key, "iso8859-1"),
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203 | txn=txn)
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204 |
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205 | def put(self, key, value, flags=0, txn=None) :
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206 | key = bytes(key, "iso8859-1")
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207 | if value != None :
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208 | value = bytes(value, "iso8859-1")
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209 | return self._db.put(key, value, flags=flags, txn=txn)
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210 |
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211 | def put_bytes(self, key, value, txn=None) :
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212 | key = bytes(key, "iso8859-1")
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213 | return self._db.put(key, value, txn=txn)
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214 |
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215 | def get(self, key, txn=None, flags=0) :
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216 | key = bytes(key, "iso8859-1")
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217 | v = self._db.get(key, txn=txn, flags=flags)
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218 | if v != None :
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219 | v = v.decode("iso8859-1")
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220 | return v
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221 |
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222 | def get_bytes(self, key, txn=None, flags=0) :
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223 | key = bytes(key, "iso8859-1")
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224 | return self._db.get(key, txn=txn, flags=flags)
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225 |
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226 | def delete(self, key, txn=None) :
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227 | key = bytes(key, "iso8859-1")
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228 | return self._db.delete(key, txn=txn)
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229 |
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230 | def close (self) :
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231 | return self._db.close()
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232 |
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233 | self.db = db_py3k(self.db)
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234 | else : # Python 2.x
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235 | pass
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236 |
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237 | # Initialize the table names list if this is a new database
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238 | txn = self.env.txn_begin()
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239 | try:
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240 | if not getattr(self.db, "has_key")(_table_names_key, txn):
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241 | getattr(self.db, "put_bytes", self.db.put) \
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242 | (_table_names_key, pickle.dumps([], 1), txn=txn)
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243 | # Yes, bare except
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244 | except:
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245 | txn.abort()
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246 | raise
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247 | else:
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248 | txn.commit()
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249 | # TODO verify more of the database's metadata?
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250 | self.__tablecolumns = {}
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251 |
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252 | def __del__(self):
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253 | self.close()
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254 |
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255 | def close(self):
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256 | if self.db is not None:
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257 | self.db.close()
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258 | self.db = None
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259 | if self.env is not None:
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260 | self.env.close()
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261 | self.env = None
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262 |
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263 | def checkpoint(self, mins=0):
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264 | try:
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265 | self.env.txn_checkpoint(mins)
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266 | except db.DBIncompleteError:
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267 | pass
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268 |
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269 | def sync(self):
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270 | try:
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271 | self.db.sync()
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272 | except db.DBIncompleteError:
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273 | pass
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274 |
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275 | def _db_print(self) :
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276 | """Print the database to stdout for debugging"""
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277 | print "******** Printing raw database for debugging ********"
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278 | cur = self.db.cursor()
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279 | try:
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280 | key, data = cur.first()
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281 | while 1:
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282 | print repr({key: data})
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283 | next = cur.next()
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284 | if next:
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285 | key, data = next
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286 | else:
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287 | cur.close()
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288 | return
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289 | except db.DBNotFoundError:
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290 | cur.close()
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291 |
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292 |
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293 | def CreateTable(self, table, columns):
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294 | """CreateTable(table, columns) - Create a new table in the database.
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295 |
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296 | raises TableDBError if it already exists or for other DB errors.
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297 | """
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298 | assert isinstance(columns, list)
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299 |
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300 | txn = None
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301 | try:
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302 | # checking sanity of the table and column names here on
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303 | # table creation will prevent problems elsewhere.
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304 | if contains_metastrings(table):
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305 | raise ValueError(
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306 | "bad table name: contains reserved metastrings")
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307 | for column in columns :
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308 | if contains_metastrings(column):
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309 | raise ValueError(
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310 | "bad column name: contains reserved metastrings")
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311 |
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312 | columnlist_key = _columns_key(table)
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313 | if getattr(self.db, "has_key")(columnlist_key):
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314 | raise TableAlreadyExists, "table already exists"
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315 |
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316 | txn = self.env.txn_begin()
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317 | # store the table's column info
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318 | getattr(self.db, "put_bytes", self.db.put)(columnlist_key,
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319 | pickle.dumps(columns, 1), txn=txn)
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320 |
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321 | # add the table name to the tablelist
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322 | tablelist = pickle.loads(getattr(self.db, "get_bytes",
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323 | self.db.get) (_table_names_key, txn=txn, flags=db.DB_RMW))
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324 | tablelist.append(table)
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325 | # delete 1st, in case we opened with DB_DUP
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326 | self.db.delete(_table_names_key, txn=txn)
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327 | getattr(self.db, "put_bytes", self.db.put)(_table_names_key,
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328 | pickle.dumps(tablelist, 1), txn=txn)
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329 |
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330 | txn.commit()
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331 | txn = None
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332 | except db.DBError, dberror:
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333 | if txn:
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334 | txn.abort()
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335 | if sys.version_info[0] < 3 :
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336 | raise TableDBError, dberror[1]
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337 | else :
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338 | raise TableDBError, dberror.args[1]
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339 |
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340 |
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341 | def ListTableColumns(self, table):
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342 | """Return a list of columns in the given table.
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343 | [] if the table doesn't exist.
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344 | """
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345 | assert isinstance(table, str)
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346 | if contains_metastrings(table):
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347 | raise ValueError, "bad table name: contains reserved metastrings"
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348 |
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349 | columnlist_key = _columns_key(table)
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350 | if not getattr(self.db, "has_key")(columnlist_key):
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351 | return []
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352 | pickledcolumnlist = getattr(self.db, "get_bytes",
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353 | self.db.get)(columnlist_key)
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354 | if pickledcolumnlist:
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355 | return pickle.loads(pickledcolumnlist)
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356 | else:
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357 | return []
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358 |
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359 | def ListTables(self):
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360 | """Return a list of tables in this database."""
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361 | pickledtablelist = self.db.get_get(_table_names_key)
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362 | if pickledtablelist:
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363 | return pickle.loads(pickledtablelist)
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364 | else:
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365 | return []
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366 |
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367 | def CreateOrExtendTable(self, table, columns):
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368 | """CreateOrExtendTable(table, columns)
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369 |
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370 | Create a new table in the database.
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371 |
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372 | If a table of this name already exists, extend it to have any
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373 | additional columns present in the given list as well as
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374 | all of its current columns.
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375 | """
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376 | assert isinstance(columns, list)
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377 |
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378 | try:
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379 | self.CreateTable(table, columns)
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380 | except TableAlreadyExists:
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381 | # the table already existed, add any new columns
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382 | txn = None
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383 | try:
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384 | columnlist_key = _columns_key(table)
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385 | txn = self.env.txn_begin()
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386 |
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387 | # load the current column list
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388 | oldcolumnlist = pickle.loads(
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389 | getattr(self.db, "get_bytes",
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390 | self.db.get)(columnlist_key, txn=txn, flags=db.DB_RMW))
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391 | # create a hash table for fast lookups of column names in the
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392 | # loop below
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393 | oldcolumnhash = {}
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394 | for c in oldcolumnlist:
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395 | oldcolumnhash[c] = c
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396 |
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397 | # create a new column list containing both the old and new
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398 | # column names
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399 | newcolumnlist = copy.copy(oldcolumnlist)
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400 | for c in columns:
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401 | if not oldcolumnhash.has_key(c):
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402 | newcolumnlist.append(c)
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403 |
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404 | # store the table's new extended column list
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405 | if newcolumnlist != oldcolumnlist :
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406 | # delete the old one first since we opened with DB_DUP
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407 | self.db.delete(columnlist_key, txn=txn)
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408 | getattr(self.db, "put_bytes", self.db.put)(columnlist_key,
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409 | pickle.dumps(newcolumnlist, 1),
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410 | txn=txn)
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411 |
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412 | txn.commit()
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413 | txn = None
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414 |
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415 | self.__load_column_info(table)
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416 | except db.DBError, dberror:
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417 | if txn:
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418 | txn.abort()
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419 | if sys.version_info[0] < 3 :
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420 | raise TableDBError, dberror[1]
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421 | else :
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422 | raise TableDBError, dberror.args[1]
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423 |
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424 |
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425 | def __load_column_info(self, table) :
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426 | """initialize the self.__tablecolumns dict"""
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427 | # check the column names
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428 | try:
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429 | tcolpickles = getattr(self.db, "get_bytes",
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430 | self.db.get)(_columns_key(table))
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431 | except db.DBNotFoundError:
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432 | raise TableDBError, "unknown table: %r" % (table,)
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433 | if not tcolpickles:
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434 | raise TableDBError, "unknown table: %r" % (table,)
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435 | self.__tablecolumns[table] = pickle.loads(tcolpickles)
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436 |
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437 | def __new_rowid(self, table, txn) :
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438 | """Create a new unique row identifier"""
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439 | unique = 0
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440 | while not unique:
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441 | # Generate a random 64-bit row ID string
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442 | # (note: might have <64 bits of true randomness
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443 | # but it's plenty for our database id needs!)
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444 | blist = []
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445 | for x in xrange(_rowid_str_len):
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446 | blist.append(random.randint(0,255))
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447 | newid = struct.pack('B'*_rowid_str_len, *blist)
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448 |
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449 | if sys.version_info[0] >= 3 :
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450 | newid = newid.decode("iso8859-1") # 8 bits
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451 |
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452 | # Guarantee uniqueness by adding this key to the database
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453 | try:
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454 | self.db.put(_rowid_key(table, newid), None, txn=txn,
|
---|
455 | flags=db.DB_NOOVERWRITE)
|
---|
456 | except db.DBKeyExistError:
|
---|
457 | pass
|
---|
458 | else:
|
---|
459 | unique = 1
|
---|
460 |
|
---|
461 | return newid
|
---|
462 |
|
---|
463 |
|
---|
464 | def Insert(self, table, rowdict) :
|
---|
465 | """Insert(table, datadict) - Insert a new row into the table
|
---|
466 | using the keys+values from rowdict as the column values.
|
---|
467 | """
|
---|
468 |
|
---|
469 | txn = None
|
---|
470 | try:
|
---|
471 | if not getattr(self.db, "has_key")(_columns_key(table)):
|
---|
472 | raise TableDBError, "unknown table"
|
---|
473 |
|
---|
474 | # check the validity of each column name
|
---|
475 | if not self.__tablecolumns.has_key(table):
|
---|
476 | self.__load_column_info(table)
|
---|
477 | for column in rowdict.keys() :
|
---|
478 | if not self.__tablecolumns[table].count(column):
|
---|
479 | raise TableDBError, "unknown column: %r" % (column,)
|
---|
480 |
|
---|
481 | # get a unique row identifier for this row
|
---|
482 | txn = self.env.txn_begin()
|
---|
483 | rowid = self.__new_rowid(table, txn=txn)
|
---|
484 |
|
---|
485 | # insert the row values into the table database
|
---|
486 | for column, dataitem in rowdict.items():
|
---|
487 | # store the value
|
---|
488 | self.db.put(_data_key(table, column, rowid), dataitem, txn=txn)
|
---|
489 |
|
---|
490 | txn.commit()
|
---|
491 | txn = None
|
---|
492 |
|
---|
493 | except db.DBError, dberror:
|
---|
494 | # WIBNI we could just abort the txn and re-raise the exception?
|
---|
495 | # But no, because TableDBError is not related to DBError via
|
---|
496 | # inheritance, so it would be backwards incompatible. Do the next
|
---|
497 | # best thing.
|
---|
498 | info = sys.exc_info()
|
---|
499 | if txn:
|
---|
500 | txn.abort()
|
---|
501 | self.db.delete(_rowid_key(table, rowid))
|
---|
502 | if sys.version_info[0] < 3 :
|
---|
503 | raise TableDBError, dberror[1], info[2]
|
---|
504 | else :
|
---|
505 | raise TableDBError, dberror.args[1], info[2]
|
---|
506 |
|
---|
507 |
|
---|
508 | def Modify(self, table, conditions={}, mappings={}):
|
---|
509 | """Modify(table, conditions={}, mappings={}) - Modify items in rows matching 'conditions' using mapping functions in 'mappings'
|
---|
510 |
|
---|
511 | * table - the table name
|
---|
512 | * conditions - a dictionary keyed on column names containing
|
---|
513 | a condition callable expecting the data string as an
|
---|
514 | argument and returning a boolean.
|
---|
515 | * mappings - a dictionary keyed on column names containing a
|
---|
516 | condition callable expecting the data string as an argument and
|
---|
517 | returning the new string for that column.
|
---|
518 | """
|
---|
519 |
|
---|
520 | try:
|
---|
521 | matching_rowids = self.__Select(table, [], conditions)
|
---|
522 |
|
---|
523 | # modify only requested columns
|
---|
524 | columns = mappings.keys()
|
---|
525 | for rowid in matching_rowids.keys():
|
---|
526 | txn = None
|
---|
527 | try:
|
---|
528 | for column in columns:
|
---|
529 | txn = self.env.txn_begin()
|
---|
530 | # modify the requested column
|
---|
531 | try:
|
---|
532 | dataitem = self.db.get(
|
---|
533 | _data_key(table, column, rowid),
|
---|
534 | txn=txn)
|
---|
535 | self.db.delete(
|
---|
536 | _data_key(table, column, rowid),
|
---|
537 | txn=txn)
|
---|
538 | except db.DBNotFoundError:
|
---|
539 | # XXXXXXX row key somehow didn't exist, assume no
|
---|
540 | # error
|
---|
541 | dataitem = None
|
---|
542 | dataitem = mappings[column](dataitem)
|
---|
543 | if dataitem <> None:
|
---|
544 | self.db.put(
|
---|
545 | _data_key(table, column, rowid),
|
---|
546 | dataitem, txn=txn)
|
---|
547 | txn.commit()
|
---|
548 | txn = None
|
---|
549 |
|
---|
550 | # catch all exceptions here since we call unknown callables
|
---|
551 | except:
|
---|
552 | if txn:
|
---|
553 | txn.abort()
|
---|
554 | raise
|
---|
555 |
|
---|
556 | except db.DBError, dberror:
|
---|
557 | if sys.version_info[0] < 3 :
|
---|
558 | raise TableDBError, dberror[1]
|
---|
559 | else :
|
---|
560 | raise TableDBError, dberror.args[1]
|
---|
561 |
|
---|
562 | def Delete(self, table, conditions={}):
|
---|
563 | """Delete(table, conditions) - Delete items matching the given
|
---|
564 | conditions from the table.
|
---|
565 |
|
---|
566 | * conditions - a dictionary keyed on column names containing
|
---|
567 | condition functions expecting the data string as an
|
---|
568 | argument and returning a boolean.
|
---|
569 | """
|
---|
570 |
|
---|
571 | try:
|
---|
572 | matching_rowids = self.__Select(table, [], conditions)
|
---|
573 |
|
---|
574 | # delete row data from all columns
|
---|
575 | columns = self.__tablecolumns[table]
|
---|
576 | for rowid in matching_rowids.keys():
|
---|
577 | txn = None
|
---|
578 | try:
|
---|
579 | txn = self.env.txn_begin()
|
---|
580 | for column in columns:
|
---|
581 | # delete the data key
|
---|
582 | try:
|
---|
583 | self.db.delete(_data_key(table, column, rowid),
|
---|
584 | txn=txn)
|
---|
585 | except db.DBNotFoundError:
|
---|
586 | # XXXXXXX column may not exist, assume no error
|
---|
587 | pass
|
---|
588 |
|
---|
589 | try:
|
---|
590 | self.db.delete(_rowid_key(table, rowid), txn=txn)
|
---|
591 | except db.DBNotFoundError:
|
---|
592 | # XXXXXXX row key somehow didn't exist, assume no error
|
---|
593 | pass
|
---|
594 | txn.commit()
|
---|
595 | txn = None
|
---|
596 | except db.DBError, dberror:
|
---|
597 | if txn:
|
---|
598 | txn.abort()
|
---|
599 | raise
|
---|
600 | except db.DBError, dberror:
|
---|
601 | if sys.version_info[0] < 3 :
|
---|
602 | raise TableDBError, dberror[1]
|
---|
603 | else :
|
---|
604 | raise TableDBError, dberror.args[1]
|
---|
605 |
|
---|
606 |
|
---|
607 | def Select(self, table, columns, conditions={}):
|
---|
608 | """Select(table, columns, conditions) - retrieve specific row data
|
---|
609 | Returns a list of row column->value mapping dictionaries.
|
---|
610 |
|
---|
611 | * columns - a list of which column data to return. If
|
---|
612 | columns is None, all columns will be returned.
|
---|
613 | * conditions - a dictionary keyed on column names
|
---|
614 | containing callable conditions expecting the data string as an
|
---|
615 | argument and returning a boolean.
|
---|
616 | """
|
---|
617 | try:
|
---|
618 | if not self.__tablecolumns.has_key(table):
|
---|
619 | self.__load_column_info(table)
|
---|
620 | if columns is None:
|
---|
621 | columns = self.__tablecolumns[table]
|
---|
622 | matching_rowids = self.__Select(table, columns, conditions)
|
---|
623 | except db.DBError, dberror:
|
---|
624 | if sys.version_info[0] < 3 :
|
---|
625 | raise TableDBError, dberror[1]
|
---|
626 | else :
|
---|
627 | raise TableDBError, dberror.args[1]
|
---|
628 | # return the matches as a list of dictionaries
|
---|
629 | return matching_rowids.values()
|
---|
630 |
|
---|
631 |
|
---|
632 | def __Select(self, table, columns, conditions):
|
---|
633 | """__Select() - Used to implement Select and Delete (above)
|
---|
634 | Returns a dictionary keyed on rowids containing dicts
|
---|
635 | holding the row data for columns listed in the columns param
|
---|
636 | that match the given conditions.
|
---|
637 | * conditions is a dictionary keyed on column names
|
---|
638 | containing callable conditions expecting the data string as an
|
---|
639 | argument and returning a boolean.
|
---|
640 | """
|
---|
641 | # check the validity of each column name
|
---|
642 | if not self.__tablecolumns.has_key(table):
|
---|
643 | self.__load_column_info(table)
|
---|
644 | if columns is None:
|
---|
645 | columns = self.tablecolumns[table]
|
---|
646 | for column in (columns + conditions.keys()):
|
---|
647 | if not self.__tablecolumns[table].count(column):
|
---|
648 | raise TableDBError, "unknown column: %r" % (column,)
|
---|
649 |
|
---|
650 | # keyed on rows that match so far, containings dicts keyed on
|
---|
651 | # column names containing the data for that row and column.
|
---|
652 | matching_rowids = {}
|
---|
653 | # keys are rowids that do not match
|
---|
654 | rejected_rowids = {}
|
---|
655 |
|
---|
656 | # attempt to sort the conditions in such a way as to minimize full
|
---|
657 | # column lookups
|
---|
658 | def cmp_conditions(atuple, btuple):
|
---|
659 | a = atuple[1]
|
---|
660 | b = btuple[1]
|
---|
661 | if type(a) is type(b):
|
---|
662 | if isinstance(a, PrefixCond) and isinstance(b, PrefixCond):
|
---|
663 | # longest prefix first
|
---|
664 | return cmp(len(b.prefix), len(a.prefix))
|
---|
665 | if isinstance(a, LikeCond) and isinstance(b, LikeCond):
|
---|
666 | # longest likestr first
|
---|
667 | return cmp(len(b.likestr), len(a.likestr))
|
---|
668 | return 0
|
---|
669 | if isinstance(a, ExactCond):
|
---|
670 | return -1
|
---|
671 | if isinstance(b, ExactCond):
|
---|
672 | return 1
|
---|
673 | if isinstance(a, PrefixCond):
|
---|
674 | return -1
|
---|
675 | if isinstance(b, PrefixCond):
|
---|
676 | return 1
|
---|
677 | # leave all unknown condition callables alone as equals
|
---|
678 | return 0
|
---|
679 |
|
---|
680 | if sys.version_info[0] < 3 :
|
---|
681 | conditionlist = conditions.items()
|
---|
682 | conditionlist.sort(cmp_conditions)
|
---|
683 | else : # Insertion Sort. Please, improve
|
---|
684 | conditionlist = []
|
---|
685 | for i in conditions.items() :
|
---|
686 | for j, k in enumerate(conditionlist) :
|
---|
687 | r = cmp_conditions(k, i)
|
---|
688 | if r == 1 :
|
---|
689 | conditionlist.insert(j, i)
|
---|
690 | break
|
---|
691 | else :
|
---|
692 | conditionlist.append(i)
|
---|
693 |
|
---|
694 | # Apply conditions to column data to find what we want
|
---|
695 | cur = self.db.cursor()
|
---|
696 | column_num = -1
|
---|
697 | for column, condition in conditionlist:
|
---|
698 | column_num = column_num + 1
|
---|
699 | searchkey = _search_col_data_key(table, column)
|
---|
700 | # speedup: don't linear search columns within loop
|
---|
701 | if column in columns:
|
---|
702 | savethiscolumndata = 1 # save the data for return
|
---|
703 | else:
|
---|
704 | savethiscolumndata = 0 # data only used for selection
|
---|
705 |
|
---|
706 | try:
|
---|
707 | key, data = cur.set_range(searchkey)
|
---|
708 | while key[:len(searchkey)] == searchkey:
|
---|
709 | # extract the rowid from the key
|
---|
710 | rowid = key[-_rowid_str_len:]
|
---|
711 |
|
---|
712 | if not rejected_rowids.has_key(rowid):
|
---|
713 | # if no condition was specified or the condition
|
---|
714 | # succeeds, add row to our match list.
|
---|
715 | if not condition or condition(data):
|
---|
716 | if not matching_rowids.has_key(rowid):
|
---|
717 | matching_rowids[rowid] = {}
|
---|
718 | if savethiscolumndata:
|
---|
719 | matching_rowids[rowid][column] = data
|
---|
720 | else:
|
---|
721 | if matching_rowids.has_key(rowid):
|
---|
722 | del matching_rowids[rowid]
|
---|
723 | rejected_rowids[rowid] = rowid
|
---|
724 |
|
---|
725 | key, data = cur.next()
|
---|
726 |
|
---|
727 | except db.DBError, dberror:
|
---|
728 | if sys.version_info[0] < 3 :
|
---|
729 | if dberror[0] != db.DB_NOTFOUND:
|
---|
730 | raise
|
---|
731 | else :
|
---|
732 | if dberror.args[0] != db.DB_NOTFOUND:
|
---|
733 | raise
|
---|
734 | continue
|
---|
735 |
|
---|
736 | cur.close()
|
---|
737 |
|
---|
738 | # we're done selecting rows, garbage collect the reject list
|
---|
739 | del rejected_rowids
|
---|
740 |
|
---|
741 | # extract any remaining desired column data from the
|
---|
742 | # database for the matching rows.
|
---|
743 | if len(columns) > 0:
|
---|
744 | for rowid, rowdata in matching_rowids.items():
|
---|
745 | for column in columns:
|
---|
746 | if rowdata.has_key(column):
|
---|
747 | continue
|
---|
748 | try:
|
---|
749 | rowdata[column] = self.db.get(
|
---|
750 | _data_key(table, column, rowid))
|
---|
751 | except db.DBError, dberror:
|
---|
752 | if sys.version_info[0] < 3 :
|
---|
753 | if dberror[0] != db.DB_NOTFOUND:
|
---|
754 | raise
|
---|
755 | else :
|
---|
756 | if dberror.args[0] != db.DB_NOTFOUND:
|
---|
757 | raise
|
---|
758 | rowdata[column] = None
|
---|
759 |
|
---|
760 | # return the matches
|
---|
761 | return matching_rowids
|
---|
762 |
|
---|
763 |
|
---|
764 | def Drop(self, table):
|
---|
765 | """Remove an entire table from the database"""
|
---|
766 | txn = None
|
---|
767 | try:
|
---|
768 | txn = self.env.txn_begin()
|
---|
769 |
|
---|
770 | # delete the column list
|
---|
771 | self.db.delete(_columns_key(table), txn=txn)
|
---|
772 |
|
---|
773 | cur = self.db.cursor(txn)
|
---|
774 |
|
---|
775 | # delete all keys containing this tables column and row info
|
---|
776 | table_key = _search_all_data_key(table)
|
---|
777 | while 1:
|
---|
778 | try:
|
---|
779 | key, data = cur.set_range(table_key)
|
---|
780 | except db.DBNotFoundError:
|
---|
781 | break
|
---|
782 | # only delete items in this table
|
---|
783 | if key[:len(table_key)] != table_key:
|
---|
784 | break
|
---|
785 | cur.delete()
|
---|
786 |
|
---|
787 | # delete all rowids used by this table
|
---|
788 | table_key = _search_rowid_key(table)
|
---|
789 | while 1:
|
---|
790 | try:
|
---|
791 | key, data = cur.set_range(table_key)
|
---|
792 | except db.DBNotFoundError:
|
---|
793 | break
|
---|
794 | # only delete items in this table
|
---|
795 | if key[:len(table_key)] != table_key:
|
---|
796 | break
|
---|
797 | cur.delete()
|
---|
798 |
|
---|
799 | cur.close()
|
---|
800 |
|
---|
801 | # delete the tablename from the table name list
|
---|
802 | tablelist = pickle.loads(
|
---|
803 | getattr(self.db, "get_bytes", self.db.get)(_table_names_key,
|
---|
804 | txn=txn, flags=db.DB_RMW))
|
---|
805 | try:
|
---|
806 | tablelist.remove(table)
|
---|
807 | except ValueError:
|
---|
808 | # hmm, it wasn't there, oh well, that's what we want.
|
---|
809 | pass
|
---|
810 | # delete 1st, incase we opened with DB_DUP
|
---|
811 | self.db.delete(_table_names_key, txn=txn)
|
---|
812 | getattr(self.db, "put_bytes", self.db.put)(_table_names_key,
|
---|
813 | pickle.dumps(tablelist, 1), txn=txn)
|
---|
814 |
|
---|
815 | txn.commit()
|
---|
816 | txn = None
|
---|
817 |
|
---|
818 | if self.__tablecolumns.has_key(table):
|
---|
819 | del self.__tablecolumns[table]
|
---|
820 |
|
---|
821 | except db.DBError, dberror:
|
---|
822 | if txn:
|
---|
823 | txn.abort()
|
---|
824 | if sys.version_info[0] < 3 :
|
---|
825 | raise TableDBError, dberror[1]
|
---|
826 | else :
|
---|
827 | raise TableDBError, dberror.args[1]
|
---|