Method and system for printing oversized layout file based on cloud service

Abstract

The invention discloses a printing method and system for an oversized layout file based on cloud service, and relates to the technical field of printing, and the method comprises the steps that a printer receives a printing message segmented into a plurality of network messages, obtains the size of a layout file needing to be printed from the network messages, and if the size of the layout file exceeds a preset printer available memory security value, the printer can print the oversized layout file; if yes, obtaining printing work order information from the network message, reconstructing the network message and then sending the network message to a cloud server, and simultaneously sending the printer available memory security value to the cloud server; after the cloud server receives the network message, a version file is separated; according to the available memory security value of the printer, recombining the available memory security value into a plurality of segmented files with the size not exceeding the value; and the printer continuously receives the segmented files from the cloud server, and constructs a printing task for each segmented file according to the printing work order. According to the invention, the memory limitation of the printer is broken through, the printing of the ultra-large format file is realized, the interaction between the user and the cloud server is not needed, and the user experience is guaranteed.

Description

Technical Field

[0001] The present invention relates to the field of printing technology, and in particular to a cloud service-based printing method and system for very large format files. Background Art

[0002] Traditional printers can only receive and print streaming files, such as PCL, PostScript, etc. Streaming files serve as a print description language, which allows the printer to print after receiving part of the print data, such as a page of content. In this case, the printing application needs to first convert the file into a streaming file, and this part of the work usually requires a print driver to complete. In recent years, in order to provide users with a better printing experience, driver-free printing has become the development direction of printing. One implementation of driver-free printing is that the printer supports direct printing of layout files, such as PDF, OFD, etc. The printing application can uniformly output the files as a universal layout file such as PDF or OFD, and then send it directly to the printer.

[0003] However, the layout file must be transferred to the printer in its entirety before the printer can analyze the entire file and generate raster image information for each page. Due to limited printer memory resources, oversized layout files that exceed the printer's memory capacity cannot be received and printed, which can easily lead to system crashes due to insufficient memory. Summary of the Invention

[0004] In order to solve the above defects or shortcomings, the present invention provides a method and system for printing ultra-large format files based on cloud services, which breaks through the memory limitation of the printer and realizes driver-free printing of ultra-large format files.

[0005] One aspect of the present invention provides a method for printing an oversized format file based on a cloud service, comprising: The printer receives print message data sent by the print client and is divided into multiple network messages. The printer obtains the size of the layout file to be printed from the network message according to the printing protocol. If the size of the layout file exceeds the preset printer available memory safety value, the printer obtains the print work order information from the network message, reconstructs the network message, and sends it to the cloud server. At the same time, the printer sends the printer available memory safety value to the cloud server. After receiving the reconstructed network message and the printer's available memory safety value sent by the printer, the cloud server reassembles all the network messages into a print message, separates the layout file from the print message, and reassembles the layout file into a plurality of split files according to the printer's available memory safety value, wherein the size of the split files does not exceed the printer's available memory safety value, renames the split files according to the page numbers, packages the split files, and sends them to the printer in sequence according to the page numbers. When receiving the network message, the cloud server does not check the host attribute value of the HTTP packet header in the network message; The printer receives the split files sent by the cloud server and constructs a print task for each of the split files according to the print work order information.

[0006] Furthermore, the step of reconstructing the network message and sending it to the cloud server includes: Change the source port in the TCP header of each network message to the local port of the printer, change the destination port to the service port of the cloud server, and recalculate and update the TCP header checksum; Change the source IP address of each network message's IP header to the printer's IP address, and the destination IP address to the cloud server's IP address. Recalculate and update the IP header checksum. Send the reconstructed network message to the cloud server and delete the network message that has been processed and successfully sent.

[0007] Furthermore, the reorganizing of the layout file into a plurality of split files according to the printer's available memory safety value includes: Parsing the file structure of the layout file, and generating a folder framework for split files according to the file structure, wherein the folder framework includes a page folder, a resource folder, and a document information description file; Extract the contents except the page folder from the layout file, copy them and put them into the folder other than the page folder of the split file; Extracting part of the page content from the layout file in the order of page numbers, copying and putting it into the page folder; Checking whether the size of the split file exceeds the safety value of the available memory of the printer, and if so, reducing the number of pages contained in the split file until the size does not exceed the safety value of the available memory of the printer; Modify the document information description file of the split file according to the split file page content.

[0008] Furthermore, the method further includes removing public resources irrelevant to the partial page content according to the public resource ID referenced by the partial page content.

[0009] Furthermore, the public resources include fonts, graphics and images.

[0010] Optionally, the cloud server uses its own stored character library to parse the characters of the layout file and adds the font data to the split files of the layout file.

[0011] Another aspect of the present invention provides a cloud service-based printing system for very large format files, comprising: The print client is used to send print message data divided into multiple network messages to the printer; A printer, comprising a print service interface, an analysis module, a forwarding module and a print processing module; the print service interface is used to receive print message data sent by a print client and divided into multiple network messages; the analysis module is used to obtain the size of the layout file to be printed from the network message according to the printing protocol, and if the size of the layout file exceeds a preset printer available memory safety value, obtain print work order information from the network message; the forwarding module is used to establish a connection with a cloud server, reconstruct the network message and send it to the cloud server, and at the same time send the printer available memory safety value to the cloud server; the print processing module is used to receive the divided files sent by the cloud server, and construct a print task for each of the divided files according to the print work order information; The cloud server includes a large file processing service interface and a layout file segmentation tool. The large file processing service interface is used to receive the reconstructed network message and the printer's available memory safety value sent by the printer, reorganize all the network messages into print messages, and separate the layout files from the print messages. When the large file processing service interface receives the network message, it does not check the host attribute value of the HTTP header in the network message; the layout file segmentation tool is used to reorganize the layout file into several split files according to the printer's available memory safety value, the size of the split files does not exceed the printer's available memory safety value, the split files are renamed according to page numbers, and the split files are packaged and sent to the printer in order of page numbers.

[0012] Furthermore, the forwarding module is further configured to: Change the source port in the TCP header of each network message to the local port of the printer, change the destination port to the service port of the cloud server, and recalculate and update the TCP header checksum; Change the source IP address of each network message's IP header to the printer's IP address, and the destination IP address to the cloud server's IP address. Recalculate and update the IP header checksum. Send the reconstructed network message to the cloud server and delete the network message that has been processed and successfully sent.

[0013] Furthermore, the layout file segmentation tool is further used to: Parsing the file structure of the layout file, and generating a folder framework for split files according to the file structure, wherein the folder framework includes a page folder, a resource folder, and a document information description file; Extract the contents except the page folder from the layout file, copy them and put them into the folder other than the page folder of the split file; Extracting part of the page content from the layout file in the order of page numbers, copying and putting it into the page folder; Checking whether the size of the split file exceeds the safety value of the available memory of the printer, and if so, reducing the number of pages contained in the split file until the size does not exceed the safety value of the available memory of the printer; Modify the document information description file of the split file according to the split file page content.

[0014] Furthermore, the layout file segmentation tool is further used to remove public resources irrelevant to the partial page content based on the public resource ID referenced by the partial page content.

[0015] The present invention provides a method and system for printing oversized format files based on cloud services. The method processes oversized format files by combining a printer with a cloud server, determines the format file size through network messages, and enables the cloud server for auxiliary printing when the format file exceeds the safety value of the printer's available memory. The method receives and forwards network messages to the cloud server while receiving them, thereby avoiding the print file from being completely resident in the printer's memory, avoiding the risk of memory overflow, breaking through the printer's memory limit, and realizing the printing of oversized format files. The cloud server reorganizes the oversized format file into split files based on the format file structure, removes irrelevant resources based on the public resource ID referenced by the pages of the split files, and realizes that the split files maintain the integrity of being independently printable while also keeping resources streamlined and reducing the file size. The printing work order information extracted from the network message is used to reconstruct the printing task into a sub-printing task for each split file. The printer receives and prints in the order of the split files, and the user perceives it as a continuous operation without the need for manual intervention. The printing method provided in this embodiment breaks through the printer's memory limit, realizes the printing of oversized format files, and does not require the user to interact with the cloud server, thus ensuring user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Other features, objects and advantages of the present application will become more apparent upon reading the detailed description of non-limiting embodiments made with reference to the following drawings: Figure 1 This is a flowchart of a method for printing an oversized format file based on a cloud service provided by an embodiment of the present application; Figure 2 This is a structural diagram of a printing system for very large format files based on cloud services provided by an embodiment of the present application. DETAILED DESCRIPTION

[0017] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] The terms used in the embodiments of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The singular forms "a", "the" and "the" used in the embodiments of the present invention are also intended to include plural forms, unless the context clearly indicates other meanings.

[0019] It should be understood that although the terms first, second, third, etc. may be used to describe the acquisition modules in the embodiments of the present invention, the acquisition modules should not be limited to these terms. These terms are only used to distinguish the acquisition modules from each other.

[0020] The word "if," as used herein, may be interpreted as "at the time of" or "when" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrases "if it is determined" or "if (stated condition or event) is detected" may be interpreted as "when it is determined" or "in response to the determination" or "when detecting (stated condition or event)" or "in response to detecting (stated condition or event)," depending on the context.

[0021] It should be noted that the directional terms such as "upper," "lower," "left," and "right" described in the embodiments of the present invention are described from the perspectives shown in the accompanying drawings and should not be construed as limiting the embodiments of the present invention. Furthermore, in the context, it should be understood that when an element is referred to as being formed "on" or "under" another element, it can be formed not only directly "on" or "under" the other element, but also indirectly "on" or "under" the other element through an intermediate element.

[0022] refer to Figure 1 The present invention provides a method for printing an oversized format file based on cloud services, comprising the following steps: In step S101, the printer receives print message data, which is segmented into multiple network messages, sent by the print client. The printer obtains the size of the layout file to be printed from the network message according to the print protocol. If the size of the layout file exceeds a preset printer available memory safety value, the printer obtains print work order information from the network message, reconstructs the network message, and sends it to the cloud server. The printer also sends the printer available memory safety value to the cloud server. Specifically, the printing client generates a print message for the layout file to be printed. When transmitting through the network, the print message is split and a TCP header and an IP header are added to form multiple network messages sent to the printer, wherein the print message includes an HTTP header, print work order information and a layout file, the network message includes an IP header, a TCP header and a print message segmentation block, the print message segmentation block includes an HTTP header and a segmented layout file, wherein the print message segmentation block of the first network message also includes print work order information. In particular, when the HTTP header and print work order information in the print message are too large, when the print message is split into a network message, part of the print work order information will be split into the second network message. The size of the layout file to be printed is obtained from the network message according to the printing protocol. Exemplarily, the IPP (Internet Printing Protocol) protocol is used to obtain the size of the layout file to be printed from the print order information in the network message. The LPD (Line Printer Daemon) protocol is used to obtain the size of the layout file to be printed from the HTTP header. The layout file size is compared with a preset safety value for the printer's available memory. Exemplarily, the preset safety value for the printer's available memory is 50% of the printer's memory. If the layout file size does not exceed 50% of the printer's memory, the printer directly prints the layout file after receiving it in full. If the layout file size exceeds 50% of the printer's memory, the print order information is obtained from the network message to prepare for the subsequent cloud-based printing process. The print order information includes metadata and control instructions related to the print job, such as the number of copies, page range, paper size, duplex printing settings, and job name. Exemplarily, the printer obtains the print order information from the network message according to the IPP protocol: print pages 9-15, print 5 copies.

[0023] The printer establishes a connection with the cloud server, such as through a TCP socket program. While continuously receiving network messages, the printer reconstructs the received network messages and sends them to the cloud server. The specific steps include: Modify the source port of each network packet's TCP header to the printer's local port, and the destination port to the cloud server's service port. Recalculate and update the TCP header checksum. For example, the printing application port is 1111 and the IP address is 111.111.111, the printer's local port is 2222 and the IP address is 222.222.222, and the cloud server port is 3333 and the IP address is 233.233.233. Change the source port of the data packet's TCP header from 1111 to 2222 and the destination port from 2222 to 3333. Since the source and destination ports of the TCP header are modified, the TCP checksum needs to be recalculated and updated. Change the source IP address of each network message IP header to the printer IP address, change the destination IP address to the cloud server IP address, and recalculate and update the IP header checksum. For example, change the source IP address of the network message IP header from 111.111.111 to 222.222.222, and the destination IP address from 222.222.222 to 233.233.233. Since the source port and destination port of the IP header are modified, the IP checksum needs to be recalculated and updated. The reconstructed network message is sent to the cloud server, and the network message that has been processed and successfully sent is deleted. Each network message is forwarded while being received until all the print message data of the layout file to be printed is sent to the cloud server, so as to avoid the layout file that exceeds the safety value of the printer's available memory from being completely resident in the printer memory, avoiding the risk of memory overflow. At the same time, the safety value of the printer's available memory is also sent to the cloud server. After all data is sent, the TCP session is disconnected.

[0024] Step S102: After receiving the reconstructed network message and the printer's available memory safety value from the printer, the cloud server reconstructs all of the network messages into print messages, separates the layout file from the print message, and reconstructs the layout file into a plurality of split files according to the printer's available memory safety value, wherein the size of the split files does not exceed the printer's available memory safety value, renames the split files according to the page numbers, packages the split files, and sends them to the printer in sequence according to the page numbers. When receiving the network message, the cloud server does not check the host attribute value of the HTTP header in the network message. Specifically, after receiving all reconstructed network messages, the cloud server reassembles all network messages into print messages, and separates and reassembles the complete print work order information and layout file from the print messages according to the format agreed upon by the printing protocol. Generally, according to the HTTP header processing protocol of the web server, if the host attribute value does not point to the host name of its own web server, the message will be discarded. Therefore, the cloud server used in this embodiment does not check the host attribute value of the HTTP header in the network message when receiving the network message; Reorganize the complete layout file into a number of split files whose sizes do not exceed the printer's available memory safety value according to the received printer's available memory safety value, the specific steps including: Parse the file structure of the layout file, and generate a folder framework for splitting the files based on the file structure. The folder framework includes page folders, resource folders, and document information description files. For example, the layout file is an OFD document with a total of 100 pages. The OFD document is essentially a compressed package. The total folder OFD_File includes Doc documents and OFD document information description file OFD.xml. There can be multiple Doc documents. In this embodiment, only one Doc document is included. The Doc document includes folders and files such as page folder Pages, resource folder Res, and Doc document information description file Document.xml. Among them, OFD.xml is used to describe the entire OFD document. There is only one OFD.xml file in an OFD document compressed package. Document.xml is used to describe the Doc document to which it belongs. In a complete OFD document, pages The folder Pages includes page folders Page_0 to Page_100 for all pages, and the resource folder Res includes local resources and public resources such as fonts, graphics, and images. The 100-page OFD document is divided into 10 new OFD documents, and each new OFD document contains 10 pages of document content in page number order. The folder framework of each reorganized new OFD document is constructed according to the file structure of the above OFD document. For example, a folder framework of the first new OFD document OFD_1 containing pages 0-10 is constructed, including the folder Doc_1 and the OFD document information description file OFD.xml. The folder Doc_1 includes the page folder Pages, the resource folder Res, and the Doc document information description file Document.xml, etc., wherein the page folder Pages includes page folders Page_0 to Page_10 for pages 0-10; Extract the contents except the page folder from the layout file, copy them and put them into a folder other than the page folder of the split file; for example, extract OFD.xml from the complete OFD document and put it directly into the main folder OFD_1 of the split file; extract the local resources and public resources except the page folder Pages and copy them into the resource folder Res of the folder Doc_1; Extract part of the page content from the layout file in the order of page numbers, copy it and put it into the page folder; for example, extract all the content in the page folders Page_0 to Page_10 from the complete OFD document, copy it and put it into the page folders Page_0 to Page_10 in the folder Doc_1; Check whether the size of the split file exceeds the safe value of the printer's available memory. If so, reduce the number of pages contained in the split file until its size does not exceed the safe value of the printer's available memory. If the split file is too small, add more pages until the size of the split file does not exceed the safe value of the printer's available memory, so as to avoid a decrease in transmission efficiency due to over-splitting. Preferably, resources not related to the extracted pages, such as unused fonts, can be removed based on the public resource ID referenced in the page folder to further reduce the size of the split file. Modify the basic information about the current document in OFD.xml and Document.xml according to the page content of the split file. For example, if the current new OFD document contains 10 pages, modify the number of pages in OFD.xml to 10; Rename the split files according to page numbers. For example, rename the new OFD document OFD_1 containing pages 0-10 to print0-10.ofd, and rename the new OFD document OFD_2 containing pages 11-20 to print11-20.ofd. Package them and send them to the printer in order of page numbers.

[0025] Therefore, by parsing the layout file structure to extract and reorganize the split files, the memory occupied by each split file is reduced, and each split file retains complete page information such as coordinates, fonts and graphics, which can effectively avoid content confusion caused by cross-page splitting.

[0026] Step S103: The printer receives the split files sent by the cloud server and constructs a print task for each of the split files according to the print work order information.

[0027] Specifically, after the printer receives the packaged segmented files, it constructs a new print job task for each packaged segmented file according to the original print work order and prints it. For example, the original print work order content is to print pages 9-15 and print 5 copies. The first print job task is constructed: print pages 9-10 in print0-10.ofd, print 5 copies, and send them to the printer to complete printing; the second print job task is constructed: print pages 11-15 in print11-20.ofd, print 5 copies, and send them to the printer to complete printing, until the processing of all segmented files is completed.

[0028] Furthermore, due to memory limitations and lack of font library, the printer may easily cause garbled text or fail to print. The layout file needs to embed the font type file according to the standard to ensure that the printer can print without relying on the local font library. However, if the layout file does not embed the font, the cloud server can use its own stored font library, such as TTF font library, to parse the characters and add the font type data to the split files of the layout file. The computing-intensive tasks such as font library parsing are completed by the cloud service, which can also greatly reduce the memory usage of the printer.

[0029] In addition, the printing method of this embodiment requires the printer to be connected to the Internet and obtain the user's consent to send the printed content to the supplier's cloud server when necessary, and all transmissions are in secure transmission mode.

[0030] This embodiment provides a method for printing oversized format files based on cloud services. The method processes oversized format files by combining the printer with a cloud server, determines the format file size through network messages, and enables the cloud server for auxiliary printing when the format file exceeds the safe value of the printer's available memory. The method receives and forwards network messages to the cloud server simultaneously, preventing the print file from completely residing in the printer's memory, avoiding the risk of memory overflow, breaking through the printer's memory limit, and achieving the printing of oversized format files. The cloud server reorganizes the oversized format file into split files based on the format file structure, removes irrelevant resources based on the public resource ID referenced by the pages of the split files, and achieves the split files to maintain the integrity of being independently printable while also streamlining resources and reducing file size. The printing work order information obtained through the network message is reconstructed into sub-printing tasks for each split file. The printer receives and prints the split files in order, and the user perceives it as a continuous operation without the need for manual intervention. The printing method provided by this embodiment breaks through the printer's memory limit, achieves the printing of oversized format files, and does not require the user to interact with the cloud server, thus ensuring user experience.

[0031] See also Figure 2 Another embodiment of the present invention further provides a printing system 200 for very large format files based on cloud services, including a printing client 210, a printer 220 and a cloud server 230. The system 200 can execute the printing method in the method embodiment.

[0032] Specifically, the print client 210 is used to send print message data divided into multiple network messages to the printer; The printer 220 includes a print service interface 221, an analysis module 222, a forwarding module 223, and a print processing module 224. The print service interface 221 is used to receive print message data segmented into multiple network messages sent by the print client 210. The analysis module 222 is used to obtain the size of the layout file to be printed from the network message according to the printing protocol. If the size of the layout file exceeds a preset printer available memory safety value, print work order information is obtained from the network message. The forwarding module 223 is used to establish a connection with the cloud server 230, reconstruct the network message and send it to the cloud server 230, and simultaneously send the printer available memory safety value to the cloud server 230. The print processing module 224 is used to receive the segmented files sent by the cloud server 230 and construct a print task for each segmented file according to the print work order information. The cloud server 230 includes a large file processing service interface 231 and a layout file segmentation tool 232. The large file processing service interface 231 is used to receive the reconstructed network message and the printer's available memory safety value sent by the printer, reorganize all the network messages into print messages, and separate the layout files from the print messages. When the large file processing service interface receives the network message, it does not check the host attribute value of the HTTP header in the network message; the layout file segmentation tool 232 is used to reorganize the layout file into several split files according to the printer's available memory safety value, and the size of the split files does not exceed the printer's available memory safety value. The split files are renamed according to page numbers, packaged, and sent to the printer in order of page numbers.

[0033] Furthermore, the forwarding module 223 is further configured to: Change the source port in the TCP header of each network message to the local port of the printer, change the destination port to the service port of the cloud server, and recalculate and update the TCP header checksum; Change the source IP address of each network message's IP header to the printer's IP address, and the destination IP address to the cloud server's IP address. Recalculate and update the IP header checksum. Send the reconstructed network message to the cloud server and delete the network message that has been processed and successfully sent; Furthermore, the layout file segmentation tool 232 is further used to: Parsing the file structure of the layout file, and generating a folder framework for split files according to the file structure, wherein the folder framework includes a page folder, a resource folder, and a document information description file; Extract the contents except the page folder from the layout file, copy them and put them into the folder other than the page folder of the split file; Extracting part of the page content from the layout file in the order of page numbers, copying and putting it into the page folder; Checking whether the size of the split file exceeds the safety value of the available memory of the printer, and if so, reducing the number of pages contained in the split file until the size does not exceed the safety value of the available memory of the printer; Modify the document information description file of the split file according to the split file page content.

[0034] Furthermore, the layout file segmentation tool 232 is further used to: According to the public resource ID referenced by the partial page content, public resources irrelevant to the partial page content are removed.

[0035] It should be noted that the printing system provided in this embodiment corresponds to a technical solution that can be used to execute various method embodiments. Its implementation principle and technical effects are similar to those of the method and will not be repeated here.

[0036] The above description is merely a preferred embodiment of the present invention. Those skilled in the art should understand that the scope of the present invention is not limited to technical solutions formed by specific combinations of the above-mentioned technical features. It also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents, without departing from the above-mentioned disclosure. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A method for printing large format files based on cloud services, characterized in that: include: The printer receives print message data sent by the print client and is divided into multiple network messages. The printer obtains the size of the layout file to be printed from the network message according to the printing protocol. If the size of the layout file exceeds the preset printer available memory safety value, the printer obtains the print work order information from the network message, reconstructs the network message, and sends it to the cloud server. At the same time, the printer sends the printer available memory safety value to the cloud server. After receiving the reconstructed network message and the printer's available memory safety value sent by the printer, the cloud server reassembles all the network messages into a print message, separates the layout file from the print message, and reassembles the layout file into a plurality of split files according to the printer's available memory safety value, wherein the size of the split files does not exceed the printer's available memory safety value, renames the split files according to the page numbers, packages the split files, and sends them to the printer in sequence according to the page numbers. When receiving the network message, the cloud server does not check the host attribute value of the HTTP packet header in the network message; The printer receives the split files sent by the cloud server and constructs a print task for each of the split files according to the print work order information.

2. The method for printing an oversized format file based on cloud service according to claim 1, characterized in that: The step of reconstructing the network message and sending it to the cloud server includes: Change the source port in the TCP header of each network message to the local port of the printer, change the destination port to the service port of the cloud server, and recalculate and update the TCP header checksum; Change the source IP address of each network message's IP header to the printer's IP address, and the destination IP address to the cloud server's IP address. Recalculate and update the IP header checksum. Send the reconstructed network message to the cloud server and delete the network message that has been processed and successfully sent.

3. The method for printing an oversized format file based on cloud service according to claim 1, characterized in that: The step of reorganizing the format file into a plurality of split files according to the available memory security value of the printer includes: Parsing the file structure of the layout file, and generating a folder framework for split files according to the file structure, wherein the folder framework includes a page folder, a resource folder, and a document information description file; Extract the contents except the page folder from the layout file, copy them and put them into the folder other than the page folder of the split file; Extracting part of the page content from the layout file in the order of page numbers, copying and putting it into the page folder; Checking whether the size of the split file exceeds the safety value of the available memory of the printer, and if so, reducing the number of pages contained in the split file until the size does not exceed the safety value of the available memory of the printer; Modify the document information description file of the split file according to the split file page content.

4. The method for printing an oversized format file based on cloud service according to claim 3, characterized in that: The method further includes removing public resources irrelevant to the partial page content according to the public resource ID referenced by the partial page content.

5. The method for printing an oversized format file based on cloud service according to claim 4, characterized in that: The common resources include fonts, graphics and images.

6. The method for printing an oversized format file based on cloud service according to claim 1, characterized in that: Also includes: The cloud server uses its own stored character library to parse the characters of the layout file and adds the font data of the font to the split files of the layout file.

7. A printing system for large format files based on cloud services, characterized in that: include: The print client is used to send print message data divided into multiple network messages to the printer; Printer, including a print service interface, an analysis module, a forwarding module and a print processing module; The print service interface is used to receive print message data sent by the print client and divided into multiple network messages; the analysis module is used to obtain the size of the layout file to be printed from the network message according to the printing protocol, and if the size of the layout file exceeds a preset printer available memory safety value, obtain the print work order information from the network message; the forwarding module is used to establish a connection with the cloud server, reconstruct the network message and send it to the cloud server, and at the same time send the printer available memory safety value to the cloud server; The printing processing module is used to receive the split files sent by the cloud server and construct a printing task for each of the split files according to the printing work order information; The cloud server includes a large file processing service interface and a layout file segmentation tool. The large file processing service interface is used to receive the reconstructed network message and the printer's available memory safety value sent by the printer, reorganize all the network messages into print messages, and separate the layout files from the print messages. When the large file processing service interface receives the network message, it does not check the host attribute value of the HTTP header in the network message; the layout file segmentation tool is used to reorganize the layout file into several split files according to the printer's available memory safety value, the size of the split files does not exceed the printer's available memory safety value, the split files are renamed according to page numbers, and the split files are packaged and sent to the printer in order of page numbers.

8. The cloud service-based printing system for large format files according to claim 7, characterized in that: The forwarding module is further configured to: Change the source port in the TCP header of each network message to the local port of the printer, change the destination port to the service port of the cloud server, and recalculate and update the TCP header checksum; Change the source IP address of each network message's IP header to the printer's IP address, and the destination IP address to the cloud server's IP address. Recalculate and update the IP header checksum. Send the reconstructed network message to the cloud server and delete the network message that has been processed and successfully sent.

9. The cloud-based printing system for large format files according to claim 7, characterized in that: The layout file segmentation tool is further used to: Parsing the file structure of the layout file, and generating a folder framework for split files according to the file structure, wherein the folder framework includes a page folder, a resource folder, and a document information description file; Extract the contents except the page folder from the layout file, copy them and put them into the folder other than the page folder of the split file; Extracting part of the page content from the layout file in the order of page numbers, copying and putting it into the page folder; Checking whether the size of the split file exceeds the safety value of the available memory of the printer, and if so, reducing the number of pages contained in the split file until the size does not exceed the safety value of the available memory of the printer; Modify the document information description file of the split file according to the split file page content.

10. The cloud service-based printing system for large format files according to claim 9, characterized in that: The layout file segmentation tool is further used to remove public resources irrelevant to the partial page content based on the public resource ID referenced by the partial page content.

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