Add persistent data store module

1 files changed, 92 insertions, 0 deletions

diff --git a/lib/bb/persist_data.py b/lib/bb/persist_data.py
new file mode 100644
index 000000000..a0263e453
--- /dev/null
+++ b/lib/bb/persist_data.py
@@ -0,0 +1,92 @@
+# BitBake Persistent Data Store
+#
+# Copyright (C) 2007        Richard Purdie
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License along
+# with this program; if not, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+import bb, os
+
+try:
+    import sqlite3
+except ImportError:
+    bb.msg.fatal(bb.msg.domain.PersistData, "Importing sqlite3 failed, please install it.")
+
+class PersistData:
+    """
+    BitBake Persistent Data Store
+
+    Used to store data in a central location such that other threads/tasks can 
+    access them at some future date.
+
+    The "domain" is used as a key to isolate each data pool and in this 
+    implementation corresponds to an SQL table. The SQL table consists of a 
+    simple key and value pair.
+
+    Why sqlite? It handles all the locking issues for us.
+    """
+    def __init__(self, d):
+        self.cachedir = bb.data.getVar("CACHE", d, True)
+        self.cachedir = "/tmp"
+        if self.cachedir in [None, '']:
+            bb.msg.fatal(bb.msg.domain.PersistData, "Please set the 'CACHE' variable.")
+        try:
+            os.stat(self.cachedir)
+        except OSError:
+            bb.mkdirhier(self.cachedir)
+
+        self.cachefile = os.path.join(self.cachedir,"bb_persist_data.sqlite3")
+        bb.msg.debug(1, bb.msg.domain.PersistData, "Using '%s' as the persistent data cache" % self.cachefile)
+
+        self.connection = sqlite3.connect(self.cachefile, isolation_level=None)
+
+    def addDomain(self, domain):
+        """
+        Should be called before any domain is used
+        Creates it if it doesn't exist.
+        """
+        self.connection.execute("CREATE TABLE IF NOT EXISTS %s(key TEXT, value TEXT);" % domain)
+
+    def delDomain(self, domain):
+        """
+        Removes a domain and all the data it contains
+        """
+        self.connection.execute("DROP TABLE IF EXISTS %s;" % domain)
+
+    def getValue(self, domain, key):
+        """
+        Return the value of a key for a domain
+        """
+        data = self.connection.execute("SELECT * from %s where key=?;" % domain, [key])
+        for row in data:
+            return row[1]
+
+    def setValue(self, domain, key, value):
+        """
+        Sets the value of a key for a domain
+        """
+        data = self.connection.execute("SELECT * from %s where key=?;" % domain, [key])
+        rows = 0
+        for row in data:
+            rows = rows + 1
+        if rows:
+            self.connection.execute("UPDATE %s SET value=? WHERE key=?;" % domain, [value, key])
+        else:
+            self.connection.execute("INSERT into %s(key, value) values (?, ?);" % domain, [key, value])
+
+    def delValue(self, domain, key):
+        """
+        Deletes a key/value pair
+        """
+        self.connection.execute("DELETE from %s where key=?;" % domain, [key])
+