#
#C. Macon    - October 04, 2017, Modify VDatum MultiCPU for GDAL translate LZW Compression
#
#

import os, time, glob, Queue, threading, math, multiprocessing


############################# Variables to edit ################################
gdalPath = 'C:\\GDAL'                       # Change path to the GDAL install folder
nProc = multiprocessing.cpu_count() - 12    # Number of cpu's to use for multi-threading.  Use 12 (or other #) less than the machine has
################################################################################

start = time.time()

# Input path and files
tifPath = os.getcwd()
print('     Compressing TIF files in %s')%(os.getcwd())
tiff = glob.glob('*.tif')

# Output path
if not os.path.isdir("GDAL_lzw"):
    os.makedirs("GDAL_lzw")
outTifDir = '\\'.join( [tifPath, "GDAL_lzw"] )

# Organize batch jobs for multi-cpu processing
nTif = len( tiff )
nBatches = nTif
tifPerBatch = nTif/nBatches
if tifPerBatch < 1:
    tifPerBatch = 1
lzwCmd = []

for i in range( 0, nTif, tifPerBatch ):

    tiffIdx1 = i
    tiffIdx2 = i+tifPerBatch
    if tiffIdx2 > nTif: # last batch could have fewer files
        tiffIdx2 = nTif

    tifFiles = tiff[tiffIdx1:tiffIdx2]
    inTifFiles = ';'.join(tifPath+'\\'+str(f) for f in tifFiles)
    outTifFiles = ';'.join(outTifDir+'\\'+str(f) for f in tifFiles)

    lzwCmdStr =  gdalPath + '\\gdal_translate.exe -co "COMPRESS=LZW" ' + inTifFiles + ' ' + outTifFiles

    lzwCmd.append(lzwCmdStr)

os.chdir(gdalPath)

queue = Queue.Queue()

class ThreadJobs(threading.Thread):

    def __init__(self, queue):
        threading.Thread.__init__(self)
        self.queue = queue

    def run(self):
        while True:
            # get job from queue
            myJob = self.queue.get()
            inCmd = myJob
            os.system(inCmd)

            # signal queue job is done
            self.queue.task_done()

def main():
    # spawn a pool of processes, and let the queue manage them
    for i in range(nProc):
        t = ThreadJobs(queue)
        t.setDaemon(True)
        t.start()
    # populate queue with jobs
    for cmd in lzwCmd:
        queue.put(cmd)
    # wait on the queue until everything has been processed
    queue.join()
    return 'Done'

main()

print '\n\nProcessing completed in: %s' % ((time.time() - start)/60),'minutes'

del start