btestchunk.py

This is an example of record update and retrieve chunk based on btest.py .

import sys
import struct
import math
import os
import platform
 
if (platform.system() == "Windows"):
    sys.path.append("C:\\Program Files\\Actian\\Zen\\bin")
else:
    sys.path.append("/usr/local/actianzen/lib64")
 
import btrievePython
 
min_x = 0
max_x = 255
btrieveFileName = "squaresAndSquareRoots.btr"
chunkFormat = "<BHd"
chunkLength = 11
 
# If the incorrect number of arguments were given.
if (len(sys.argv) != 2):
    sys.exit("Usage: " + os.path.basename(sys.argv[0]) + " uint8_value")
 
integerValue = int(sys.argv[1])
 
# If integerValue is out of range.
if (integerValue < min_x) or (integerValue > max_x):
    sys.exit("Usage: " + os.path.basename(sys.argv[0]) + " uint8_value")
 
btrieveClient = btrievePython.BtrieveClient()
assert(btrieveClient != None)
 
btrieveFileAttributes = btrievePython.BtrieveFileAttributes()
assert(btrieveFileAttributes != None)
 
rc = btrieveFileAttributes.SetFixedRecordLength(chunkLength)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveFileAttributes::SetFixedRecordLength():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
 
rc = btrieveFileAttributes.SetVariableLengthRecordsMode(btrievePython.Btrieve.VARIABLE_LENGTH_RECORDS_MODE_YES)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveFileAttributes::SetVariableLengthRecordsMode():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
 
rc = btrieveClient.FileCreate(btrieveFileAttributes, btrieveFileName, btrievePython.Btrieve.CREATE_MODE_OVERWRITE)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveClient::FileCreate():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
 
btrieveFile = btrievePython.BtrieveFile()
assert(btrieveFile != None)
 
rc = btrieveClient.FileOpen(btrieveFile, btrieveFileName, None, btrievePython.Btrieve.OPEN_MODE_NORMAL)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveClient::FileOpen():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
 
# For all the values of x.
chunk = struct.pack(chunkFormat, 0, 0, 0)
 
rc = btrieveFile.RecordCreate(chunk)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveFile::RecordCreate():%d:%s.\n"  % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
 
for i in range(min_x, max_x + 1):
    chunk = struct.pack(chunkFormat, i, i * i, math.sqrt(i))
 
    if (i == min_x):
        
        rc = btrieveFile.RecordUpdateChunk(0, chunk)
        assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveFile::RecordUpdateChunk():%d:%s.\n"  % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
        
    else:
        
        rc = btrieveFile.RecordUpdateChunk(chunk)
        assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveFile::RecordUpdateChunk():%d:%s.\n"  % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
        
 
# print chunk
chunk = struct.pack(chunkFormat, 0, 0, 0)
 
rc = btrieveFile.RecordRetrieveFirst(btrievePython.Btrieve.INDEX_NONE, chunk)
assert(rc == chunkLength), "Error: BtrieveFile::RecordRetrieveFirst():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(btrieveFile.GetLastStatusCode()))
 
for i in range(min_x, max_x + 1):
    # If this is the first chunk.
    if (i == min_x):
        
        rc = btrieveFile.RecordRetrieveChunk(0, chunkLength, chunk)
        assert(rc == chunkLength), "Error: BtrieveFile::RecordRetrieveChunk():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(btrieveFile.GetLastStatusCode()))
        
    else:
        
        rc = btrieveFile.RecordRetrieveChunk(chunkLength, chunk)
        assert(rc == chunkLength), "Error: BtrieveFile::RecordRetrieveChunk():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(btrieveFile.GetLastStatusCode()))
        
 
    x, xSquared, xSquareRoot = struct.unpack(chunkFormat, chunk)
 
    # If key has been found.
    if (x == integerValue):
        break
 
print ("chunk:", struct.unpack(chunkFormat, chunk))
 
rc = btrieveClient.FileClose(btrieveFile)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveClient::FileClose():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(rc))
 
rc = btrieveClient.FileDelete(btrieveFileName)
assert(rc == btrievePython.Btrieve.STATUS_CODE_NO_ERROR), "Error: BtrieveClient::FileDelete():%d:%s.\n" % (rc, btrievePython.Btrieve_StatusCodeToString(rc))