JP4241920B2 - Data communication method - Google Patents

Description

  The present invention relates to a data communication method, and more particularly to a data communication method in a WWW system that transmits and receives data between a WWW (World Wide Web) server and a client via a network, and more specifically, a local proxy and a remote proxy. Data transmission and reception and data processing in the proxy.

In response to a request from a WWW browser on the client PC (personal computer) side using the Internet, a file such as a home page held in the WWW server is acquired and displayed on the client PC on a daily basis. Yes.
Since a large amount of files held by the WWW server usually include contents such as text data, images, music, and moving images, when the files are transmitted to the client PC, these contents are also transferred.

  When a file related to a certain home page and related content are transmitted from the WWW server to the client PC, a call setting occurs on the network for each content, and a file containing a large amount of content is transmitted from the WWW server to the client PC each time. Will be. In this case, it takes time for the content to be acquired on the PC, and depending on the type of content, a considerable time is required for display, or some content may not be received from the WWW server.

  2. Description of the Related Art Conventionally, in order to reduce network call settings and improve transfer efficiency, a WWW system has been proposed in which a file requested by a WWW browser and contents referenced from the file are collectively transferred from the WWW server proxy to the WWW browser. Yes. This technique is disclosed in, for example, Japanese Patent Laid-Open No. 2000-20415 (Patent Document 1).

  In addition, in order to improve the throughput of data transfer in the WWW system, a cache server is provided as a WWW server, files and contents accessed once by the WWW browser are held in this cache server, and a cache server is received when a new file is received In response to a request from a client PC, if the target file exists in this cache server, all data files necessary for display are transferred from this cache server in one request. Technology is known. This type of technology is disclosed in, for example, Japanese Patent Application Laid-Open No. 2002-149533 (Patent Document 2).

JP 2000-20415 A

JP 2002-149533 A

  According to the above-mentioned patent document 1, contents included in a file requested from a browser are transferred to a request source all at once. Therefore, for example, as shown in FIG. 14, when 8 contents from B to I are included in one Web page A, until all of these 9 contents are acquired and processed collectively in the WWW server, That transfer is not done. Further, since the server performs the syntax check of the Web page A and collects many contents, the load on the server also increases.

However, none of the above-mentioned documents specifically mentions how to improve the transfer efficiency of requested content and a method for reducing the load on the server side. In addition, processing such as syntax check of content received on the client side is not specifically disclosed.
An object of the present invention is to provide a data communication method and a proxy that improve data transfer efficiency between a local site and a remote site.
Another object of the present invention is to provide a data communication method and a proxy system that reduce the load on the server side by checking the syntax of the content on the client side.

The data communication method between a local proxy and a remote proxy according to the present invention includes a step of receiving a file acquisition request from a browser and transmitting the request to the remote proxy, and the remote proxy transmits the request to an associated Web server. Then, receiving the response and sending the response to the local proxy, and the local proxy analyzes the received response and , based on the analysis result, an object list for acquiring the object included in the response create a, and transmits to the remote proxy, the to the browser sending a response not including the object, remote proxy, an object in an object list received, acquired from the associated Web server, Transmitting a response to the over local proxy, the local proxy, a communication method having the steps of transmitting from the response received from the remote proxy entity objects in the browser, the.

Preferably, the browser sequentially displays local frames from the response received from the local proxy until it displays a frame that does not include all objects on the display, and until the entities of all objects included in the frame are obtained. Transmitting a request to the server and obtaining an object entity for the request.

The remote proxy preferably packs and compresses the data of one or more objects obtained from the associated Web server as a response to the local proxy, and the local proxy receives Decompressing and unpacking the compressed response data, and storing the data of the object entity in the cache memory.
In a preferred example, the response data including no object is transmitted from the local proxy to the browser to display a frame not including the object on the display unit, and the remote proxy displays the object included in the object list to the associated Web server. The processing steps acquired from are performed in parallel.
As a result, the state that nothing is displayed on the display device continues on the local proxy side until all objects can be acquired by the Web server as in the past, and as a result, it takes a long time to display all objects. It can be avoided. That is, according to the present invention, since the display of a frame that does not include an object and the acquisition of a related object are processed in parallel, the load on the Web server is reduced. Since the acquired objects are sequentially transmitted from the local proxy to the browser, the browser can display the acquired objects sequentially.

In the present invention, when the object list includes a plurality of objects, the communication for transmitting the substance of the object performed between the local site and the remote site is performed for each predetermined number of sessions. Can do. As a result, if the number of objects is small, the objects can be acquired in a small number of sessions, and if there are many objects, the number of sessions may be increased, and the data transfer efficiency is improved as a whole.
In a preferred example, the local proxy creates an object list based on the HTML description in the received response information sent from the remote proxy.
Also, the local proxy checks whether or not an object in the created object list is registered in the cache memory, and if it is registered, registers that object in the If Modified-Since list.
In a preferred example, when the local proxy acquires an object requested from the browser and transmits a response to the browser, the local proxy deletes information on the transmitted object from the object list.

The present invention is also grasped as a data processing method in a local proxy that performs processing for acquiring an object from a remote proxy and transmitting it to the browser in response to a request from the browser. That is, receiving a file acquisition request from the browser, sending a request to the remote proxy, analyzing the response received from the remote proxy, creating a list of objects included in the response, and in the object list Sending the object list to the remote proxy to get the object, sending the response without the object received from the remote proxy to the browser, and receiving the entity of the object related to the object list from the remote proxy A data processing method in a local proxy having a step and a step of transmitting the acquired substance data of an object to a browser.

The present invention is also understood as a program for executing the communication method or a program for executing a data processing method in the local proxy .

The present invention can also be understood as a local proxy that performs processing for acquiring an object from a remote proxy and transmitting it to the browser in response to a request from the browser. That is, the present invention is described with the basic processing unit that performs transmission and reception including the file acquisition request from the browser, and the transmission and reception of a response from the remote proxy, based on the analysis result of the response received from the remote proxy, the object to be acquired has an object list creation unit that creates a list that includes a cache memory for storing data objects received from the remote proxy, a,
The basic processing unit sends a response that does not contain an object received from the remote proxy to the browser, and sends the object list created by the object list creation unit to the remote proxy,
The basic processing unit is a local proxy characterized in that when a response including an object described in the object list is received from a remote proxy, the response including the object is transmitted to the browser.

According to the present invention, data transfer efficiency between a local site and a remote site can be improved. In addition, since the content syntax is checked on the client side, the load on the server side can be reduced.

Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.
FIG. 1 is a diagram showing an example of a network system to which an embodiment of the present invention is applied.
The remote site 1 and the local site 2 are connected via a network 3 such as the Internet or a WAN (Wide Area Network), and extended communication by HTTP is possible between the both.
The local site 2 is the client side. For example, in the environment of the ubiquitous network, the client can communicate information at any time from a company, a home, a hotel, a business facility, or the like. Assuming these various places, the client includes a plurality of PCs (personal computers) 20, and each PC 20 has a browser 21 and a local proxy (L proxy) 22. The browser 21 is application software for browsing a Web page, downloads an HTML format file, an image file, a music file, etc. through the network 3, analyzes the layout, plays it back, and displays it on the display. The L proxy 22 is a computer or software that intervenes between the browser 21 and the network 3 to connect to the network 3 and communicate information. The function and operation of the proxy 22 are characteristic of the present embodiment and will be described in detail later.

  On the other hand, the remote site 1 has a proxy server 10 and communicates with a plurality of Web servers 12 by HTTP to acquire Web information. The processing of the proxy server 10 will be described in detail later.

FIG. 2 shows a module configuration of the remote proxy (R proxy) 10 and the L proxy 22.
These modules constituting the R proxy 10 and the L proxy 22 are functions executed by software.
First, the function of the module in the L proxy 22 will be described. The basic portion 221 is a portion that performs basic processing such as initial processing and creation of child threads. The object list creation unit 222 is a processing part for creating an object list from information acquired from the R proxy 10. The unpack unit 223 is a process of cutting out the received object data in a predetermined group one by one. The decompressing unit 224 is a process for decompressing the compressed data. The cache 225 refers to a process of reading and writing target data from a memory that temporarily stores received data, that is, data such as an object that is Web information.

  In the R proxy 10, a basic portion 101 is a portion that performs basic processing such as initial processing and creation of a child thread. The pack 102 is a process for collecting a plurality of objects acquired from the Web server 12 into one. The compression 103 compresses the packed data according to a certain rule. The request generation unit 104 is a processing unit that issues a request to the target Web server 12 to acquire an object.

  Next, processing operations in the L proxy 22 and the R proxy 10 will be described with reference to the processing sequence of FIG. The processing operation in the main part will be described in detail with reference to the flowcharts of FIGS.

The L proxy 22 performs initial processing at startup (L-1). This initial process is a process for initial setting of the L proxy itself, and the activation condition is read by starting the process. In the activation condition reading process, an activation condition file including an L proxy port number, an R proxy host name or IP address, an R proxy port number, and the like is read. Subsequent to the initial process, a child thread generation process is performed (L-2). This process waits for a request from the browser 21 and activates a child thread when the request is received.
When the child thread is activated, the child thread is initialized (L-3). As shown in FIG. 4, in the initial processing of the child thread, an HTTP request is received from the browser 21 (401), and it is checked whether the same HTTP request exists in the object list (402).

The object list is a list in which objects to be acquired are registered. As an example, as shown in FIG. 11, the status, list registration time, transmission destination request pointer, response data, and URL of the object to be acquired are registered in the object list.
As a result of the check in step 402, if the same request does not exist in the object list, the process proceeds to the process of relaying the request to the R proxy (403). On the other hand, if the same request exists in the list, the process acquires the entity of the object and deletes it from the object list (404). Both processes will be described in detail later.

On the other hand, in the R proxy, initial processing is performed in the same manner (R-1). This initial processing is performed by reading an activation condition file including an R proxy port number. Subsequently, it waits for a request from the L proxy, and when a request is received, activates the child process and generates a child process (R-2).
When the R proxy receives an HTTP request from the L proxy, it generates a child process (R-2) and performs initial processing of the child process (R-3).

As shown in FIG. 8, this initial process receives an HTTP request from the L proxy (801), and determines whether the request is an extension method of the W proxy (802).
Here, the W proxy extension method is a method (protocol) characteristic of the present invention relating to data communication between the L proxy and the R proxy, and an object to be acquired by the L proxy is created as an object list. To get those objects from the R proxy by sending them to the R proxy. 1 to 3 are expressed as HTTP extended communication. The object acquisition method by this method is processing related to L-5 to L-7 in FIG. 3 and will be described in detail with reference to FIG.

  Whether or not the request is a W proxy extension method is determined by, for example, setting information indicating that it is a W proxy extension method in an HTTP request header and referring to this information. . Since the request (R-2) sent from the L proxy to the R proxy in the first stage of the communication sequence is a normal HTTP request, the flag in the header is OFF, and the request is sent to the Web server 12 as it is. Wait for receipt of a response from the Web server 12. On the other hand, when the object list is sent from the L proxy, the HTTP request header information indicates that it is an extension method. Therefore, the R proxy generates a request based on the object list and associates it with the associated Web server. Send to.

  If the result of determination in step 802 is not the W proxy extension method, processing proceeds to request / response relay processing (R-4) (803). On the other hand, if it is the W proxy extension method, the process proceeds to request generation, pack, and compression processing (R-5) (804).

  As shown in FIG. 9, the request / response relay process (R-4) is a process for transmitting an HTTP request to the related Web server 12 and acquiring a response from the Web server. That is, the acquired HTTP request is transmitted to the related Web server 12 (901), and an HTTP response is received from the Web server 12 (902). The R proxy transmits the acquired response to the L proxy (903), and ends the processing (904).

Next, the operation of HTTP extension method communication in the L proxy will be described with reference to FIG.
When a response is received from the R proxy (501), it is checked whether the content type exists in the content list (502).

  Here, the content list, as shown in FIG. 12, registers the type of content for which an object list is to be created. Normally, the content type includes, for example, text / HTML, XML, an image, a moving image, and the like. Of these, text / HTML and XML are registered in the content list. In this case, as a result of analyzing the received HTTP response, if the content type is text / HTML or XML, the contents are analyzed to create an object list. On the other hand, if the content type to be received is, for example, an image or a movie, there is no possibility that other content will be included in the content, so these images and movies are sent to the browser without being analyzed. Is done. Therefore, it is not necessary to register a content type indicating an image or a moving image in the content list, and therefore an object list is not created for an image or a moving image.

  As a result of the check in step 502, if the content type exists in the content list, an object list is created from the HTML description in the response information (503). On the other hand, when the content type is not registered in the content list, for example, when the received content is an image or a moving image, since there is no need for parsing, those responses are immediately transmitted to the browser (507). Then, a series of processing is completed.

Now, when the object list is created in step 503, it is next checked whether or not the object in the created object list is in the cache in the L proxy. Register in the “modified-since list” (504).
Here, the if modified-since list is a table for inquiring whether or not the object registered in the cache is the latest, and as shown in FIG. 13, the URL of the object registered in the cache and Register the last modification time of the object.

The object list and the if modified-since list created in this way are transmitted as an HTTP request to the R proxy according to the W proxy HTTP extension method (505). At this time, the number of sessions to be used simultaneously is determined according to the number of objects. For example, as shown in FIG. 14, if there are 8 objects from B to I, if 3 objects are sent to the L proxy in the first session, 3 objects are sent in the second session. The objects are transferred, and two objects are transferred in the third session.
On the other hand, this request in the R proxy is a process for acquiring an object in the object list, and details will be described later.

  Thereafter, the L proxy sends a response to the browser (506). In the browser, the response processing of the received HTTP is performed. The HTTP response processing is an operation for displaying the received response on a display device of a PC, for example. According to the present embodiment, this display operation and the process for acquiring the object in the R proxy are executed in parallel. At this stage, since the target object is not included in the response transmitted to the browser, only the frame of the Web page A is displayed on the display, and the object portions within the frame, for example, B to I are displayed. Nothing is displayed where it should be. However, it can be recognized from the state of the display screen that the user of the PC is waiting for acquisition of the object.

Next, processing operations (R-2 to R-7) in the R proxy that has received the object list and if modified-since will be described.
The R proxy receives a request for a session generated according to the number of objects, and generates a child process correspondingly. As described above, a child process is generated (R-2) in response to a request from the L proxy. When a child process is generated, its initial processing is performed accordingly (R-3).

As shown in the flow of FIG. 10, the R proxy performs a request generation process (101), a pack process (102) of the acquired response, and a compression process (103) of the response after the pack process.
First, in the request generation, the request transmitted by the W proxy extension method is decomposed (1011), and the request is sequentially transmitted to the related Web server 12. The Web server 12 acquires an object for each received request, and transmits the acquired object to the R proxy 11. The R proxy 11 acquires data including the object from the Web server 12 as a response (1021). Then, the acquired responses are packed together to be collected (1022). The response data subjected to the pack processing is then compressed (1031), transmitted as a response to the L proxy (1032), and a series of processing ends (1033).

  For example, as shown in FIG. 14, if URLs of eight objects B to I constituting the Web page A are registered in the object list, these B to I objects are respectively acquired from the related Web server 12. Is done. For example, if three objects are transmitted to the L proxy in one session, for example, the data of the objects B, C, and D are first subjected to pack processing and compression processing and transmitted. Similarly, the three objects E, F, and G are similarly processed, and the two objects H and I are similarly processed and transmitted to the L proxy.

Next, a response reception process on the L proxy side will be described with reference to FIG.
When the response transmitted from the R proxy is received (601), the L proxy decompresses the response information (602), and unpacks the decompressed response information, that is, performs processing for separating the object (603). The object extracted by the unpacking process is temporarily stored in a memory (for example, a buffer memory) (604).
Thereafter, the objects are sequentially fetched from the memory and registered in the cache (606), and the processing at this stage is completed (607).

  On the other hand, in the browser, no object is displayed on the display screen of the Web page A, and the display state is only in the frame. Therefore, a request for object acquisition is transmitted from the browser to the L proxy, and each time the L proxy generates a child thread, the child thread is initialized, and the object acquisition process is executed (L- 2, L-3, L-7). For example, when it is necessary to acquire the entities of the eight objects B to I in the web page A, the exchange of responses to the GET request is performed at least eight times when there is no miss.

With reference to FIG. 7, the object acquisition processing will be described.
This process checks whether the target object exists in the memory of the L proxy (701). As a result of the check, if the target object exists in the memory, the object is acquired from the memory (702) and sent as a response to the browser (705). Thereafter, the present object is deleted from the object list (706), and when all the target objects have been acquired, a series of processing ends (707). Here, the memory refers to a buffer memory that temporarily stores received objects or the above-described cache.

On the other hand, when the object has not yet been acquired from the R proxy, the object does not exist in the memory. If no object exists in the memory as described above, a response from the R proxy is waited (703). During this time, if there is a request from the browser, the request is queued and waited. Thereafter, when a response from the R proxy is received (704), the process proceeds to an operation (702) for acquiring an object from the memory. If there is a request from the browser, the response is transmitted to the browser in response to the request (705). If a request from the browser is queued and is in a standby state, responses are sequentially transmitted in response to the request.
This process is repeated until all the initially requested objects are acquired, for example, until the entities of the objects B to I are acquired. In this way, the file requested from the browser and its contents are acquired and displayed on the display screen of the PC.

As described above, according to this embodiment, the syntax check of the content is performed on the local site side, so that the load on the proxy server side is reduced. In addition, since multiple sessions can be used in communication between the local site and the remote site, data transfer efficiency is improved.
Further, since data communication between the local site and the remote site is realized by a characteristic HTTP extension method, extension to a tool other than a browser, for example, a mailer can be easily performed on the local site side. That is, HTTP and mail generally have different communication protocols between the client and the server, so it is necessary to implement a communication mechanism for each protocol. The protocol can be easily expanded. For this reason, it is possible to easily cope with the mail protocol by implementing the interfaces of the L proxy and mailer, and the R proxy and mail server.

The figure which shows the structure of the network system with which one Example of this invention is applied. The figure which shows the module structure of the remote and L proxy by one Example. The figure which shows the process sequence in the proxy system by one Example. The figure for demonstrating the operation | movement of the initial process of a child thread in the processing operation of the proxy by one Example. The figure for demonstrating the operation | movement of HTTP extension method transmission in the processing operation | movement of the proxy by one Example. The figure for demonstrating the operation | movement of the decompression | decompression, unpack, and cache registration in the processing operation | movement of the proxy by one Example. The figure for demonstrating the operation | movement of object entity acquisition in the processing operation of the proxy by one Example. The figure for demonstrating the operation | movement of the initial process of the R proxy child process in the processing operation | movement of the proxy by one Example. The figure for demonstrating the operation | movement of a request and a response relay in the processing operation of the proxy by one Example. The figure for demonstrating operation | movement, such as a request production | generation and a pack, in the processing operation of the proxy by one Example. The figure which shows the structural example of the object list in the process of the proxy of one Example. The figure which shows the structural example of the content list in the process of the proxy of one Example. The figure which shows the structural example of the if modified list | wrist in the process of the proxy of one Example. The figure which shows the example of a display screen of a browser.

Explanation of symbols

1: Remote site 2: Local site 10: Proxy server 10: R proxy 11: Web server 20: PC
21: Browser 22: L proxy

Claims (17)

In the data communication method between the local proxy and the remote proxy,
Receiving a file retrieval request from a browser and sending the request to a remote proxy;
The remote proxy sends the request to an associated web server, receives a response, and sends the response to a local proxy;
The local proxy analyzes the received response, creates an object list for acquiring the object included in the response based on the analysis result, transmits the object list to the remote proxy, and sends an object list to the browser. Sending a response that does not contain ,
A step wherein the remote proxy, to the objects included in the object list received, acquired from the associated Web server, and transmits a response to the local proxy,
The local proxy, communication method characterized by having the steps of: transmitting from the response received from the remote proxy entity object to the browser. The browser
From the response received from the local proxy, displaying a frame not including all objects on the display unit;
Sequentially transmitting requests to the local proxy until all object entities included in the frame are acquired, and acquiring object entities for the request;
The communication method according to claim 1, further comprising: The remote proxy is a step of sending, as a response, data obtained by packing and compressing the entity of one or more objects acquired from a related Web server to the local proxy;
The local proxy uncompresses and unpacks the received response data, and performs a process of storing the object data of the object in a cache memory;
The communication method according to claim 1, further comprising: Sending response data that does not contain an object from the local proxy to the browser and displaying a frame that does not contain the object on the display unit, and the remote proxy obtains the object contained in the object list from the associated Web server The communication method according to any one of claims 1 to 3, wherein the processing steps are performed in parallel. When there are a plurality of objects included in the object list, the communication for sending the entity of the object performed between the remote proxy and the local proxy is performed by dividing the predetermined number of sessions. The communication method according to claim 1. 6. The communication method according to claim 1, wherein the local proxy creates an object list based on an HTML description in the received response information transmitted from the remote proxy. The local proxy checks whether an object in the created object list is registered in the cache memory, and if registered, registers the object in the If Modified-Since list. The communication method according to claim 1. The local proxy acquires an object requested from the browser from a remote proxy and deletes information on the transmitted object from the object list when a response is transmitted to the browser. 7. The communication method according to any one of 7. In the data processing method in the local proxy that performs processing to acquire an object from the remote proxy and send it to the browser in response to a request from the browser,
In response to the file acquisition request from the browser, and sending a request to the remote proxy,
Analyzing the response received from the remote proxy and creating a list of objects included in the response;
Sending the object list to a remote proxy to obtain objects in the object list;
Sending a response received from the remote proxy that does not contain an object to the browser;
Receiving an object entity associated with the object list from the remote proxy;
Sending the acquired object entity data to the browser;
A data processing method in a local proxy. The local proxy includes a step of decompressing the received response data, unpacking the packed object, and storing the object data in the cache memory. The data processing method in the local proxy of Claim 9 characterized by these. The local proxy, a processing step of sending the response data does not include the object to the browser, to retrieve a step of displaying on the display a frame that do not contain objects, the objects included in the object list from the remote proxy 11. The data processing method in the local proxy according to claim 9 or 10, wherein the processing is performed in parallel. 12. The remote site according to claim 9 or 11, wherein when there are a plurality of objects included in the object list, the remote site receives the entity of the object from the remote proxy by dividing the number of predetermined sessions. Data processing method in the local proxy. 13. The data processing method in the local proxy according to claim 9, wherein the local proxy creates an object list from the HTML description in the received response information transmitted from the remote proxy. The local proxy checks whether an object in the created object list is registered in the cache memory, and if registered, registers the object in the If Modified-Since list. The data processing method in the local proxy of Claim 9 or 13. A program for executing the processing according to claim 1 or 9 on a computer . In a local proxy that performs processing for acquiring an object from a remote proxy in response to a request from the browser and sending it to the browser,
A basic processing unit that performs transmission / reception including a file acquisition request from the browser, and transmission / reception of a response from the remote proxy;
Based on the analysis result of the response received from the remote proxy, an object list creation unit for creating a list describing objects to be acquired;
A cache memory for storing object data received from the remote proxy,
The basic processing unit transmits a response including no object received from the remote proxy to the browser, and transmits the object list created by the object list creation unit to the remote proxy.
When the basic processing unit receives a response including an object described in the object list from the remote proxy, the basic processing unit transmits the response including the object to the browser. A content type relating to the object includes a content list for registering a type of content for which the object list is to be created,
When a response is received from the remote proxy, if the content type exists in the content list, the object creation unit creates the object list from the HTML description in the response, and the basic processing unit creates The sent object list to the remote proxy,
When the response is received from the remote proxy, if the content type does not exist in the content list, the basic processing unit transmits the response not including an object to the browser,
The basic processing unit, when an object in the created object list is stored in the cache memory, transmits the object stored in the cache memory to the browser. 16 local proxies.

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