utils.py

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"""--------------------------------------------------------------------
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 \file   utils.py

 \brief  This module contains general utility functions

 \Platform: Cross Platform
--------------------------------------------------------------------"""
import struct
import socket

"""
For IEEE754 processors this function converts a 32-bit floating point number to
a 32-bit integer representation
"""
def convert_float_to_u32(value):
    return struct.unpack('I', struct.pack('f', value))[0]

"""
For IEEE754 processors this function converts a 32-bit integer representation
of a floating point value to float representation
"""
def convert_u32_to_float(bits):
    return struct.unpack('f', struct.pack('I', bits))[0]

"""
Used to convert a byte array (string) into an array of 32-bit values
"""
def convert_byte_data_to_U32(data):

    rx_dat = [];
    k = 0;
    
    #
    # Convert the string into a byte array
    #
    
    for x in range(0,len(data)):
        rx_dat.append(ord(data[x]));
        
    number_of_u32s = (len(rx_dat)/4)

    #
    # Convert the byte array into an array of 32bit values
    #
    converted = [0]*number_of_u32s;
    for x in range(0,number_of_u32s):
        converted[x] = int((((rx_dat[k]   << 24) & 0xFF000000)) |
                        (((rx_dat[k+1] << 16) & 0x00FF0000)) |
                        (((rx_dat[k+2] << 8)  & 0x0000FF00)) |
                          (rx_dat[k+3] & 0x000000FF));

        k+=4;
        
    return converted;

"""
Used to convert an IP address string in dotted quad format to an integer
"""  
def dottedQuadToNum(ip):
    "convert decimal dotted quad string to long integer"
    return struct.unpack('I',socket.inet_aton(ip))[0]

"""
Used to convert an IP address in integer format to a dotted quad string
""" 
def numToDottedQuad(n):
    "convert long int to dotted quad string"
    return socket.inet_ntoa(struct.pack('I',n))