Source code for src.core.downloader.Downloader

#!/usr/bin/python3

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# Copyright (c) 2017 Sardegna Clima - Raffaele Bua (buele)
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# this software and associated documentation files (the "Software"), to deal in
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from src.data.database.services.products_service import ProductsService
from src.data.database.entities.product import Product
from src.data.database.entities.product import ProductStatus
from src.data.logger.logger import logger
from src.core.downloader.DownloaderJob import DownloaderJob
import threading
import queue
from collections import deque
from src.core.downloader.ConfigurationManager import ConfigurationManager
from src.core.downloader.SearchFilter import SearchFilter
from src.core.downloader.Datasource import Datasource
from src.core.processing_pipe.src.ProcessingPipeManager import ProcessingPipeManager

__author__ = "Raffaele Bua (buele)"
__copyright__ = "Copyright 2017, Sardegna Clima"
__credits__ = ["Raffaele Bua"]
__license__ = "MIT"
__version__ = "0.1"
__maintainer__ = "Raffaele Bua"
__contact__ = "info@raffaelebua.eu"
__status__ = "Development"


class Downloader:
    """ The main class of *Downloader* module, it is the entry point that receives the trigger of
        download events.
    """
    def __init__(self):
        logger.debug("(Downloader __init__)")
        self.productService = ProductsService()
        self.downloading = False
        self.configurationManager = ConfigurationManager()
        self.configuration = self.configurationManager.get_configuration()
        self.queue = queue.Queue()
        self.pending_tasks = 0
        self.datasource = Datasource(self.configuration)

    def create_search_filter(self, tile):
        """ This method generates the *SearchFilter* object from the tile name and configurations set
            by user.

            :param tile: Tile name
            :type tile: String

            :returns: Search filter object to retrieve data from datasource
            :rtype: SearchFilter

        """
        return SearchFilter(tile, self.configuration.start_date, self.configuration.end_date)

    def start(self):
        """ Download event handler. The entry point of the *Downloader* module.

        """
        logger.debug("(Downloader start) ")
        processing_pipe_manager = ProcessingPipeManager()
        processing_pipe_manager.start_processing()
        self.pending_tasks += 1
        if self.downloading:
            return
        self.downloading = True
        for tile in self.configuration.tiles:
            search_filter = self.create_search_filter(tile)
            products_list = self.datasource.get_products_list(search_filter)
            for pending_product in products_list:
                self.productService.add_new_product(Product(name=str(pending_product),
                                                            status=ProductStatus.pending))
        products = [self.queue.put(product) for product in self.productService.get_pending_products()]
        while self.pending_tasks:
            for i in range(int(self.configuration.parallel_downloads)):
                t = DownloaderJob(self.queue)
                t.daemon = True
                t.start()
            self.pending_tasks -= 1
        self.downloading = False