ADD file via upload

cache.py

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+#!/usr/bin/env python3
+
+import numpy as np
+import tensorflow as tf
+import csv
+import os
+
+def cacheName(loperand, roperand, op):
+    '''
+    Naming conventions, facilitate cache storage and loading
+    '''
+    return loperand + "_" + op + "_" + roperand
+
+def cacheSave(id, ciphertext, cacheName):
+    '''
+    This module cache the data slice to local binary file.
+
+    Note: we store the tuple in ciphertext as S16 type.
+    '''
+    cache_path = "server/P{}/".format(id) + cacheName + ".sdata"
+    sess = tf.Session()
+    if type(ciphertext) is np.ndarray:
+        tabletobesaved = ciphertext.astype("S16")
+    else:
+        ciphertext = sess.run(ciphertext)
+        tabletobesaved = ciphertext.astype("S16")
+    bytesbuffer = tabletobesaved.tobytes()
+    fd = open(cache_path, "wb")
+    fd.write(bytesbuffer)
+    fd.close()
+    '''
+    Need record the shape of cache, in order to reveal the ciphertext according to *.sdata and shape!
+    '''
+
+def cacheLoad(id, cacheName, tshape):
+    '''
+    This module read and reconstruct the ciphertext table from bytesbuffer
+    '''
+    cache_path = "server/P{}/".format(id) + cacheName + ".sdata"
+    fd = open(cache_path, "rb")
+    bytesbuffer = fd.read()
+    fd.close()
+    cipherTable = np.frombuffer(bytesbuffer, dtype = "S16", count = tshape[0]*tshape[1], offset = 0)
+    cipherTable.resize((tshape[0], tshape[1]))
+    return cipherTable
+
+def ifCached(id, cacheName):
+    '''
+    This module judge whether the ciphertext has been cached
+    '''
+    cache_path = "server/P{}/".format(id) + cacheName + ".sdata"
+    return os.path.exists(cache_path)
+
+def judgeTypes(tuple):
+    '''
+    When compute the result from the operand stack, we should judge the type of the operand:
+
+    There are three types:
+    (1) Digit: e.g. '4', '50000'        return 1
+    (2) Column: e.g. 'ID', 'deposit'            return 2
+    (3) Cipher result: e.g. [[b'ul\xcd\x11\x89\x9d\xba\xe1#'][b'\x9fIa\xcbj%8n#']...]       return 3
+
+    '''
+    if type(tuple) != str:
+        return 3
+    else:
+        if tuple.isdigit() == True:
+            return 1
+        else:
+            return 2
+
+def cacheRule(id, loperand, roperand, op):
+    '''
+    This module judge whether the subquery need to be cached:
+
+    If return true && not has been cached -> cache to local
+    If return false -> MPC directly, not cache to local
+    '''
+
+    if judgeTypes(loperand) == 2 and judgeTypes(roperand) == 2:
+        '''
+        Rule1. If there is no pure digit in the subquery, it is compared between columns
+
+        e.g. 'loan > 5000' will return false, 'loan > deposit' will return true
+        '''
+        return True
+    
+    '''
+    Rule2. 
+    '''
+
+    return False