Method for breakpoint continuous transmission of reliable file acceptance (receiving) system based on unidirectional broadcasting network

Abstract

The invention discloses a method for resuming transmission from a break-point for a reliable file receiving system on the basis of a unidirectional broadcast network, which comprises the following steps: firstly, slicing files to be transmitted according to the fixed size; secondly, attaching offset information and check information to each sliced file; thirdly, submitting a combined application data unit to a reliable multicast layer to split the application data unit into data blocks at the layer; fourthly, coding the data blocks so as to generate corresponding redundant data blocks; and fifthly, transmitting all the data blocks in a scrambled mode by a file transmission service terminal. When a user terminal receives the file, an information index file of the file is created for recording the receiving situation of the file data blocks. When the file receiving is resumed after break, information record files are checked to determine whether the transmission of the file needs to be resumed, and the transmission of the file is resumed according to the attached information. By adopting the method, the file can be received continuously from the break-point and the redundant and time-consuming write operation is skipped over to reduce writing times of a disk to protect the disk, thus the aims of reducing the I / O times and the CPU occupancy rate and saving hardware resource of a receiving end is achieved.

Description

technical field [0001] The invention belongs to the technical field of computer design and application, and in particular relates to a method for resumed transmission of a reliable file receiving system based on a one-way broadcast network. Background technique [0002] When receiving a large file on a one-way broadcast network, after receiving a large part of the file, due to special events, it is necessary to disconnect the transmission and reconnect to the network later. When receiving from the sender again, due to the inability to interact with the front-end server, the traditional two-way network-based file breakpoint resume transfer technology is no longer applicable. As a result, the entire file will be received again, so that the file will be repeatedly received and written , in this case, it takes a long time to completely receive the entire file, and the CPU usage of the client is high, and the disk reads and writes frequently. [0003] The file receiving end only...

AI Technical Summary

Problems solved by technology

This will cause a lot of repetitive work at the receiving end (especially the low-speed process of writing to disk). Consider an extreme case where a large file is divided into n application data units. If only one ADU is left unreceived in the first round All, if the reception is interrupted at this time, then all ADUs must be re-received and re-written to the disk at the next reception. Since the speed of writing to the disk is relatively slow, this will greatly increase the burden on the client, and Increased requirements for client CPU and network processing capabilities

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