add python api

api/python/.gitignore

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+*.pyc

api/python/example/PythonAPIExample.py

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+# coding: utf-8
+# zhangxiaoyang.hit#gmail.com
+# github.com/zhangxiaoyang
+
+import sys
+sys.path.append('../src')
+from GstoreConnector import GstoreConnector
+
+if __name__ == '__main__':
+    gc = GstoreConnector('127.0.0.1', 3305)
+    gc.build('LUBM10.db', 'data/LUBM_10.n3')
+    sparql = '''select ?x where {
+        ?x    <rdf:type>    <ub:UndergraduateStudent>.
+        ?y    <ub:name> <Course1>.
+        ?x    <ub:takesCourse>  ?y.
+        ?z    <ub:teacherOf>    ?y.
+        ?z    <ub:name> <FullProfessor1>.
+        ?z    <ub:worksFor>    ?w.
+        ?w    <ub:name>    <Department0>.
+    }'''
+    answer = gc.query(sparql)
+    print answer
+
+    gc.unload('LUBM10.db')
+    gc.load('LUBM10.db')
+    answer = gc.query(sparql)
+    print answer

api/python/lib/.gitignore

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+*
+!.gitignore
+

api/python/src/GstoreConnector.py

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+# coding: utf-8
+# zhangxiaoyang.hit#gmail.com
+# github.com/zhangxiaoyang
+
+import socket
+import traceback
+
+class GstoreConnector:
+
+    def _connect(self):
+        try:
+            self._sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)  
+            self._sock.connect((self.ip, self.port))  
+            return True
+        except Exception, e:
+            print 'socket disconnection error. @GstoreConnector.disconnect'
+            traceback.print_exc()
+        return False
+
+    def _disconnect(self):
+        try:
+            self._sock.close()  
+            return True
+        except Exception, e:
+            print 'socket disconnection error. @GstoreConnector.disconnect'
+            traceback.print_exc()
+        return False
+
+    def _send(self, msg):
+        data = self._pack(msg)
+        self._sock.send(data)
+        return True
+
+    def _recv(self):
+        head = self._sock.recv(4)
+        context_len = 0
+        for i in range(4):
+            context_len |= (ord(head[i]) << i * 8)
+
+        data = bytearray(context_len)
+        recv_len = 0
+        while recv_len < context_len:
+            chunk = self._sock.recv(1024)
+            data.extend(chunk)
+            recv_len += len(chunk)
+        return str(data)
+
+    def _pack(self, msg):
+        data_context = bytearray()
+        data_context.extend(msg)
+        context_len = len(data_context) + 1
+        data_len = context_len + 4
+
+        data = bytearray(data_len)
+        for i in range(4):
+            data[i] = chr((context_len >> i * 8) & 0xFF)
+        for i, _ in enumerate(data_context):
+            data[i + 4] = data_context[i]
+        data[data_len - 1] = 0
+        return data
+
+    def _communicate(f):
+        def wrapper(self, *args, **kwargs):
+            if not self._connect():
+                print 'connect to server error. @GstoreConnector.%s' % f.__name__
+                return False
+
+            if f.__name__ == 'build':
+                cmd = 'import'
+            elif f.__name__ == 'show':
+                cmd = 'show databases'
+            else:
+                cmd = f.__name__
+            params = ' '.join(map(lambda x:str(x), args))
+            full_cmd = ' '.join([
+                cmd,
+                params
+            ]).strip()
+
+            if not self._send(full_cmd):
+                print 'send %s command error. @GstoreConnector.build' % cmd
+                return False
+
+            recv_msg = self._recv()
+            self._disconnect()
+
+            succ = {
+                'load': 'load database done.',
+                'unload': 'unload database done.',
+                'import': 'import RDF file to database done.',
+                'query': None,
+                'show databases': None,
+            }
+            if cmd in succ:
+                if succ[cmd] == recv_msg:
+                    return True
+                else:
+                    return recv_msg
+            return False
+        return wrapper
+
+    def __init__(self, ip='127.0.0.1', port=3305):
+        self.ip = ip
+        self.port = port
+
+    @_communicate
+    def load(self, db_name):
+        pass
+
+    @_communicate
+    def unload(self, db_name):
+        pass
+
+    @_communicate
+    def build(self, db_name, rdf_file_path):
+        pass
+
+    @_communicate
+    def query(self, sparql):
+        pass
+
+    @_communicate
+    def show(self):
+        pass