WO2006035662A1 - Memory area managing method, browser program, and mark-up language document processor - Google Patents

Abstract

When a browser is operating in an environment in which the OS such as a built-in OS allocates a fixed memory area to an application, the whole memory area allocatable to pages is used for the first-opened first page (S13). In response to a request to open another page when the first page is open, the whole currently-free area of the memory area is used for the page (S14). If the free area is insufficient, at least a part of the memory area used for the opened pages is released to use it for the page to be opened (S16). If the free area is still insufficient, the whole memory area used by at least one of the opened pages is released to use it for the page (S20). In such a way, the efficiency of use of a memory of when pages are simultaneously opened is enhanced, thereby improving the convenience to the user.

Description

 Specification

 Memory area management method, browser program, and markup language document processing apparatus

 Technical field

 [0001] The present invention relates to a browser program and a markup language document processing apparatus for browsing a markup language document, and a memory area management method thereof.

 Background art

 [0002] “Windows” as a frame for displaying information on a display screen of a display device as a man-machine user interface for various devices controlled by a computer such as a personal computer (PC). Is often used.

 [0003] Conventionally, when an application capable of displaying a plurality of windows is operated on a device, each time a window is opened, the application acquires a memory area necessary for displaying the window, and acquires when a window is closed, When the memory area is released, the following operations are performed.

 [0004] In an OS that is usually used on a PC, such as Microsoft Corporation's Windows (registered trademark), the application flexibly secures the memory required by the application, so that the application can contain a large number of windows. It is possible to secure a memory area for opening the. For example, it is common for Internet browser applications that run on an OS such as Windows to display multiple Web pages in different windows. As with normal applications that can display multiple windows, each time a window is opened, the application acquires the memory area required to display the window. When the window is closed, the application acquires the memory area and releases the memory area.

 [0005] Further, the present invention relates to a technology for receiving and caching the encoded image data from the server on the Windows (registered trademark) machine in a client, and displaying the cached image data. An image processing method has been proposed in which cached data that has little effect on the playback image is deleted from the generated image data, and display according to the user's request is made while preventing data overflow in the cache ( Patent Document 1).

Patent Document 1: Japanese Unexamined Patent Application Publication No. 2004-145760 Patent Document 2: Japanese Patent Laid-Open No. 2003-256219

 Patent Document 3: Japanese Patent Laid-Open No. 7-334339

 Patent Document 4: Japanese Patent Laid-Open No. 2003-316591

 Non-Patent Document 1: Shigetoshi Yamamoto, Kazutoshi Arisue, “Embedded Device and Programming Language” (Interface March 2002, p. 44-48)

 Disclosure of the invention

 Problems to be solved by the invention

 [0006] On the other hand, embedded OSs used in devices called embedded devices (refer to Patent Document 2) such as mobile phones, automobiles, and various household appliances (see Patent Document 2) In some cases, a fixed memory area is allocated to the prescription, and the memory area that can be allocated to open a window cannot be allocated beyond a relatively small allocation. This is because the embedded OS does not provide a mechanism for searching for free memory and allocating it to applications (Non-patent Document 1). Therefore, in an embedded OS, in order for a browser application to open multiple pages at the same time (or to open other pages while the page is open), it is necessary to perform the operation within a fixed memory area to which system power is allocated. There is.

 [0007] One solution is to define a memory area to be allocated to a window for displaying one page, and to secure a memory area for one window each time a page needs to be opened. Conceivable. However, with this method, the memory capacity required to display a page will exceed the allocated memory area, even if there is space in the memory area allocated to another window. The page cannot be displayed, and the convenience of the user who uses the memory very poorly is low.

 [0008] On the other hand, when the maximum number of windows that can be opened at the same time is determined and another window is opened after opening one window, it is necessary to erase the lowest window and open a new window. A technology that secures a sufficient memory area and opens a new window has been proposed (Patent Document 3).

[0009] Also, a predetermined plug-in module is not related to the simultaneous display of a plurality of pages, but relates to a browser that implements various embedded data processing function extensions using a plug-in method. A technology has been proposed for deleting a plug-in module stored in a storage device when the capacity is insufficient to store another plug-in module in a storage device having a predetermined capacity for storing the module ( Patent Document 4).

 [0010] As described above, in order to open a new page in an Internet browser, erasing the previous window and releasing the memory area has the following problems. For example, on websites such as e-commerce, data must be sent again from the browser to the CGI (Common Gateway Interface) on the WWW server used for ordering and settlement. After the data is deleted, the same page is displayed. It becomes difficult to display. As a result, there is a risk of unforeseen disadvantages to users such as overlapping orders and payments. Since the data of the page to be displayed is on the network, it cannot be guaranteed that it will always be acquired when it is acquired again. This problem is particularly noticeable in a wireless communication network.

 [0011] The present invention has been made in such a background, and an object thereof is to provide a plurality of pages in a browser that operates in an environment in which a fixed memory area is allocated to an application in an OS such as an embedded OS. It is to improve the use efficiency of the memory when opening the memory at the same time, and as a result, improve the convenience of the user.

 Means for solving the problem

[0012] A memory area management method according to the present invention uses a memory area for a new page opened in an apparatus that executes a browser program that operates in an environment in which a fixed memory area is allocated to an application. If the request to open a page is the first page to be opened for the first time, the step of using the entire memory area allocatable to the page and the opening of the first page are performed. In response to a request to newly open another page in the state of V, the step of using the entire current free area of the allocatable memory area for the other page and the other newly opened page If the memory area required by a page is not enough, the page of the memory area used for the already opened page A step of releasing a memory area storing embedded information embedded therein, a step of using a free area including the released memory area for the newly opened page, and a releasing of the memory area storing the embedded information. If there is not enough free space, at least one of the already open And the step of releasing all memory areas used by the page.

 As described above, in the present invention, in order to efficiently use the memory, a predetermined memory area that can be used to open a page is provided without defining an upper limit on the number of pages that are simultaneously opened, and the first page is provided. When the page is opened, the entire predetermined memory area is used. Also, in response to a request to open another page while the first page is open, the entire current free area in the predetermined memory area is used for the other page. This allows efficient use of memory regardless of the number of pages opened simultaneously.

 [0014] In addition, if the memory area required by another newly opened page is not enough, the two-stage process is used. That is, first, by releasing the memory area that stores the embedded information embedded in the page among the memory areas used for the already opened page, a new page can be displayed (the first page described later). Memory release). In other words, by leaving the markup language document itself, it is possible to omit the process of acquiring and reinterpreting the document when it is displayed again.

 [0015] The release of the storage area containing only embedded information is particularly useful when a cache memory is provided. That is, the markup language document constituting the page and the embedded information are stored in the cache memory, and the embedded information is present in the cache memory when the page in which at least a part of the memory area is opened is reopened. Then, the embedded information can be read out from the cache memory and used. This makes it possible to quickly retrieve and redisplay the embedded information that has been erased.

[0016] If there is not enough free space even if the memory area storing the embedded information among the memory areas to be used for the already opened page is released, it is already opened as a second stage process. The step of releasing all memory areas used by at least one page is provided. That is, if there is not enough memory area to open a new page even if the part is discarded, all the data on the other page (for example, markup language document data including embedded information and corresponding data) By discarding both display data), a large amount of free space can be secured. At this time, the window-related data, that is, only the page data, ie, the setting data in the window and the display of the window By discarding data, more free space can be secured (second memory release described later).

[0017] However, in this case, before executing the step of releasing all the memory areas used by the at least one page that has already been opened, the user of the apparatus is asked for permission for the execution. It is preferable to further comprise a step. This makes it possible for the user to cancel page erasure when the page to be erased uses CGI like payment processing or search processing, and reproducibility cannot be guaranteed by page erasure. There is an effect.

 [0018] If the page still cannot be opened, only a part of the page may be opened.

 [0019] The browser program is, for example, a type that switches and displays a plurality of opened pages in one window opened on a display screen.

 [0020] The present invention can be further understood as a browser program for executing the above memory area management methods on a terminal.

 [0021] The present invention can also be understood as a markup language document processing apparatus in which a browser program is installed.

 The invention's effect

 [0022] According to the present invention, in a browser operating in an environment in which a fixed memory area is allocated to an application in an OS such as an embedded OS, the fixed memory area is assigned to the first page and subsequent pages. By using it flexibly, it is possible to increase the memory usage efficiency when opening multiple pages at the same time. As a result, user convenience can be improved.

 [0023] In addition, page information is discarded when there is a shortage of memory area, and is performed step by step according to the degree of shortage. In consideration of the speed and reproducibility of redisplay after destruction, there is a shortage of memory area. Can deal with.

 Brief Description of Drawings

FIG. 1 is a diagram showing the appearance of two examples of an apparatus to which the present invention is applied.

 2 is a block diagram illustrating a hardware configuration example of the television device illustrated in FIG. 1 (a).

FIG. 3 is a block diagram showing a hardware configuration example of the mobile phone shown in FIG. 1 (b). FIG. 4 is a diagram showing a basic software configuration of an apparatus to which the present invention is applied.

FIG. 5 is a diagram showing a software function configuration of a browser.

 FIG. 6 is an explanatory diagram of a memory area allocated to a browser in the embodiment of the present invention.

 [Fig. 7] Fig. 7 is a diagram showing various pieces of information on a page stored in a browser information area in the embodiment of the present invention.

 FIG. 8 is a diagram showing a data configuration example of a page displayed in a window in the embodiment of the present invention.

 FIG. 9 is a diagram showing the contents of various types of information stored in the browser information area 42 of FIG.

FIG. 10 is a diagram showing an example of a so-called tab browser screen as an example of a browser to which the present invention is applied.

 FIG. 11 is a diagram showing processing when page # 1 is opened in the embodiment of the present invention.

FIG. 12 is a diagram showing processing when page # 2 is opened in the embodiment of the present invention.

FIG. 13 is a diagram showing processing when page # 3 is opened in the embodiment of the present invention.

FIG. 14 is a diagram showing processing when developing image # 1 embedded in page # 3 in the embodiment of the present invention.

 [Fig. 15] Fig. 15 is a diagram showing processing when expanding image # 1 embedded in page # 3 in the embodiment of the present invention.

 FIG. 16 is a diagram showing processing (memory acquisition failure) when image # 2 embedded in page # 3 is further expanded in the embodiment of the present invention.

 FIG. 17 is a diagram showing processing (memory acquisition success) when image # 2 embedded in page # 3 is further expanded in the embodiment of the present invention.

 FIG. 18 is a flowchart showing a processing example of memory area management of the memory management function of the browser in the embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described in detail with reference to the drawings. In the following embodiment, a case will be described in which image information is erased from page display data in the first memory release. (Apparatus to which the invention is applied)

 FIG. 1 shows the appearance of two examples of a markup language document processing apparatus to which the present invention is applied. FIG. 1 (a) shows an example of a television device 55 having an Internet connection function as a first example. FIG. 2 (b) shows an example of the mobile phone 10 as a second example.

 In this example, the television device 55 in FIG. 1 (a) is an example of a television device that supports data broadcasting, that is, BML and HTML, and a dedicated remote controller 50 is attached. The television device 55 can display not only broadcasting but also information obtained via a communication network such as the Internet. The remote controller 50 is provided with channel keys and other operation keys.

 Note that the remote controller 50 may be a remote controller that does not have a color button or the like. The communication medium of the remote controller 50 is generally infrared (IrDA), but is not necessarily limited to infrared, and may be wired or wireless.

 [0029] The television device 55 shown in FIG. 1 (a) has a power indicating that it has a built-in markup language document processing device. A so-called set-top type markup language document processing device is externally attached to the television device body. It may be of a type that does.

 The mobile phone 10 shown in FIG. 1B is connected to a communication network by operating the operation unit 13 in addition to the telephone function so that web information can be browsed on the screen of the display 8. The cellular phone 10 is a foldable device in which an upper casing having a display 8 and a lower casing having an operation unit 13 including various keys such as a numeric keypad and a cursor movement operation key are coupled by a hinge unit. . However, it does not matter whether the cellular phone to which the present invention is applied is a folded type. A mobile phone connected to such a communication network and capable of browsing web information is also a kind of markup language document processing apparatus to which the present invention is applied.

 [0031] The apparatus shown in FIGS. 1 (a) and 1 (b) is a typical example of an apparatus to which the present invention is applied, and the present invention is not limited to these.

FIG. 2 is a block diagram illustrating a hardware configuration example of the television device 55. The television device 55 is an information processing device in which a browser that is effective in the present embodiment is installed, and includes a central control unit 201, a RAM 202, a ROM 203, a display driver 204, and a display. 205, a network interface 206, a user interface (UI) device interface 207, a flash memory 208, an IR light receiver 209, an antenna 211, and a broadcast receiving unit 212 corresponding to data transmission.

 [0033] The central control unit 201, the RAM 202, the ROM 203, the display driver 204, the network interface 206, the user interface (UI) device interface 207, the flash memory 208, and the broadcast receiving unit 212 are connected to each other via a bus 210. Data is exchanged and commands are exchanged via the bus 210.

 The RAM 202 is a memory that temporarily holds and stores calculation results of the central control unit 201 and data (including markup language documents) acquired by an external force. The ROM 203 is a non-volatile memory that stores programs and fixed data such as the operating system (OS) and the browser 203a, and the central control unit 201 reads these programs from the ROM 203 and follows the programs. A predetermined process is executed. The flash memory 208 is a rewritable nonvolatile memory that retains data acquired from the outside, information such as e-mail addresses and URLs (Uniform Resource Locator) for later processing. In this example, the browser 203a is stored in the ROM 203, but may be stored in the flash memory 208. The network interface 206 has a function of establishing a connection with an external network and transmitting / receiving data to / from an external network (such as the Internet), and is configured by, for example, a LAN board. The user interface device interface 207 has a function of receiving an input from the remote controller 50 by the IR light receiving unit 209 and passing it to the central control unit 201, for example. When receiving an infrared signal emitted from the remote controller 50, the Ir light receiving unit 209 has a function of converting it into an electric signal and passing it to the user interface device interface 207.

The display driver 204 has a function of receiving display information such as a document and an image from the central control unit 201 and driving the display based on the display information. The display 205 is an arbitrary display device such as a liquid crystal display device, a CRT display device, or a plasma display device, and has a function of optically displaying a screen based on a drive signal from the display driver 204. The broadcast receiving unit 212 has a function of extracting a signal of a desired channel from the broadcast wave power received by the antenna 211 and demodulating and reproducing the signal. This broadcast receiver 212 is a mobile phone It may correspond to the terrestrial data broadcast for.

 FIG. 3 shows a hardware configuration example of the mobile phone 10. Control of each unit of the mobile phone 10 is realized by program control of a central control unit (for example, CPU) 1 via the bus 11. ROM2 is a normal read-only memory that stores a control program for that purpose, an application program that is initially installed, and fixed data. The RAM 3 is a readable / writable memory that provides a temporary data storage area and work area. The flash memory 4 is a rewritable memory that stores various data as described above in a nonvolatile manner. The browser 2a is stored in the ROM 2 (but may be stored in the flash memory 4). The wireless network interface 6 is a part that performs wireless voice and data communication with the base station via the antenna 5. is there. The display driver 7 is controlled by the central control unit 1 to perform drawing processing of various kinds of information and display on the display screen of the display 8 as a display unit. The operation unit 13 is a part including user interface devices such as keys including various operation keys, a microphone, and a speaker under the control of the central control unit 1. In addition to these, the mobile phone 10 may include a transmission / reception unit such as a terrestrial data broadcast (not shown).

 [0037] (Description of the system)

 Fig. 4 shows the basic software configuration of the device to which the present invention is applied. This configuration is basically the same regardless of the device to which the present invention is applied. Browser program 23 (corresponding to 2a and 203a) as an application stored in memory such as ROM can be operated under the control of system (operating system: OS) 21. For this purpose, the system 21 allocates a fixed memory area for the application. As shown in FIG. 4, when the user is requested to start the browser, the system 21 acquires the browser memory area 26 on the memory (RAM) 25 and loads the browser program 23 on the ROM. The browser needs to execute in the memory area 26 for the browser allocated at this time and hold necessary data. As will be described later, the browser itself manages the memory area that the browser uses for each page within the range of the browser memory area 26 allocated by the OS 21.

[0038] (Software function configuration of browser) Figure 5 shows the software functional configuration of the browser.

 [0039] When there is a page acquisition instruction 30, the markup language (ML) document acquisition unit 31 acquires the ML document of the specified page. An HTML document will be described as an example of the ML document below. However, the ML document in the present invention is not limited to an HTML document. The acquired HTML document is sequentially processed by the parser 32 and the page maker 33 to generate layout information and character information. Layout information and character information are stored in memory 39 (corresponding to RAM 202 in FIG. 2 and RAM 3 in FIG. 3). On the other hand, the acquired HT ML document is cached in the memory 39 by the cache processing unit 35.

 [0040] When an image is specified by a specific tag, for example, an image tag img> in the HTML document, the image acquisition unit 36 acquires the specified image file, and the image development unit 37 The information (bitmap data) is expanded (decoded) and stored in the memory 39. On the other hand, the acquired HTML document is cached in the memory 39 by the cache processing unit 35. The layouter 34 displays character information and image information according to the layout information.

 Data is written to the memory 39 from the page maker 33, the image development unit 37, and the cache processing unit 35 through the memory manager 38. The memory manager 38 secures a memory area on the memory 39 and writes data in response to requests from various units.

 [0042] (Browser allocated memory area)

 Figure 6 shows an illustration of the memory area allocated to the browser. In the system environment according to the present embodiment, as described above, the system allocates a fixed memory area to the browser. The browser reserves a browser execution area 41 for the browser to execute in the allocated memory area and a browser information area 42 used to store data (cache data and display data) handled by the browser.

[0043] The browser according to the present embodiment uses the maximum memory area (capacity) of the browser information area 42 as one area that is not divided into pages to be displayed, in other words, windows. For example, as shown in Fig. 7, in the browser information area 42, cache information for page # 1, cache information for page # ₂ , display information for page # 1 (layout information, character information)

, Image information, etc.) and display information for page # 2. Figure 7 shows various information. The information is continuous in the browser information area 42 and forms one fragment, but it is not always necessary to be divided into a plurality of non-consecutive fragments.

[0044] (Window and page)

 In this specification, “window” means a display frame opened on the screen, and “page” means contents displayed in the window. The page specified by one URL is displayed in one window that the browser opens. Further, embedded information (for example, images, moving images, etc.) is usually embedded in the page. For example, as shown in Figure 8, a single page 610 (page # 1) contains multiple (here two) embedded information 612, 613 (image # 1, Consists of image # 2). In some cases, a page consists of multiple frames. In this case, one window is divided into multiple frames, and each frame displays a page with a different URL.

 As shown in FIG. 8, FIG. 9 shows the contents of various information stored in the browser information area 42 when this page # 1 is opened in one window 600 (window # 1). As can be seen from FIG. 9, as the cache information 710, page # 1 HTML document 711 and image original data 712 and 713 (original information of image # 1 and image # 2), that is, a compressed image file are stored. Also, as page display information 720, layout information 721 obtained by analyzing the HTML document, character information 722, image # 1 embedded in page # 1, information # 2 information 723, 724 (compressed image) Data after file expansion) is stored. Furthermore, as shown in FIG. 7, the window related information 730 includes various setting information 731 in window # 1 (for example, display font size), window # 1 frame, user interface (buttons, menus, tabs, etc.) Etc. Window # 1 display information 7 32 is stored.

FIG. 10 shows an example of a so-called tab browser screen as an example of a browser to which the present invention is applied. A tab browser is similar to a “tab” that is usually attached to a paper-based folder for managing paper files, and helps identify and select multiple windows on the display screen. A window display screen including a window provided with tab portions 62, 63, and 64 is used. Multiple windows are completely non-tabbed Due to the overlap, there is essentially only one window open on the screen 61. In a general browser, a new window is opened on the screen each time a new page is opened, and the screen overflows with windows, which makes the operation troublesome. On the other hand, the tab browser has only one effective window. When a page is created, a tab is added and displayed in the window. Therefore, a large number of windows are not generated on the screen. Therefore, only one set of the window-related information 730 shown in FIG. The page of the tab that is not currently selected is only hidden, and the page can be immediately displayed (activated) by selecting the tab. In the example of FIG. 10, tab sections 62, 63, and 64 are assigned to three pages, respectively, and the tab 64 page is currently active.

[0047] (Process when opening page # 1)

 Next, processing when opening the first page # 1 of browser power according to the present embodiment will be described.

 [0048] As shown in FIG. 11, when the HTML document of page # 1 is acquired (step (1)), the cache function 811 acquires memory for caching the page # 1 HTML document to the memory management function 814. When the request is made (step (2)), the memory management function 814 acquires the designated memory area in the memory (step (3)). Next, the cache function 811 writes the page # 1 HTML document into the memory as page # 1 cache information (step (4)).

 [0049] On the other hand, the page interpretation function 812 interprets the page # 1 HTML document and generates layout information and character information based on this, but requests the memory management function 814 to acquire memory for writing this information. (Step (5)). The memory management function 814 acquires the requested memory area on the memory (step (6)). Thereafter, the page interpretation function 812 writes layout information and character information on the memory (step (7)).

 [0050] Next, when image # 1 embedded in page # 1 is obtained (step (8)), the cache function 811 requests the memory management function 814 to acquire memory (step (9)), and the memory The management function 8 14 acquires the requested memory area on the memory (step (10)). If memory acquisition is successful, the cache function 811 caches image # 1 in memory (step (11)

) o On the other hand, the image expansion function 813 requests the memory management function 814 to acquire memory in order to decode the image file of image # 1 (step (12)). If the memory management function 814 acquires the memory area on the memory (step (13)), the image expansion function 813 expands the image # 1 and expands the image # 1 data (hereinafter image # 1) on the memory. 1 information) (step (14)).

 In this way, the memory management function 814 can secure the memory area necessary for storing the cache information and the display information with all the power of the browser information area. As a result, even if page # 1 is very large, it is possible to display using the maximum usable capacity in browser information area 42.

 [0053] (Processing when opening page # 2)

 This will be described in the case where the above-mentioned page # 1 is opened and page # 2 is further opened. Assume that page # 2 has two images # 1, # 2 embedded in it.

 [0054] The processing for the HTML document and image # 1 of page # 2 from step (1) to step (14) in Fig. 12 is performed in the same manner as described above. Acquire area and write each information. Furthermore, for image # 2 on page # 2, as with steps (8)-(: 14), get image # 2 (step (15)), cache image # 2 (step (16)- (18)) and the development data of image # 2 are written (steps (19) to (21)).

 As described above, if there is a free space in the browser information area, a plurality of pages can be opened by using the free area in the second page following the first page.

 [0056] (Process when opening page # 3)

 The case where page # 3 is opened with pages # 1 and # 2 opened will be described. Page # 3 shall have one image # 1 embedded in it.

[0057] As shown in FIG. 13, when the page # 3 HTML document is acquired (step (1)), the cache function 811 sends a memory acquisition request for caching the page # 1 HTML document to the memory management function 814. When performing (step (2)), the memory management function 814 acquires the instructed memory area as a free area in the memory (step (3)). Next, the cache function 811 writes the page # 1 HTML document in the memory (step (4)). On the other hand, the page interpretation function 812 interprets the page # 1 HTML document, generates layout information and character information based on this, and requests the memory management function 814 to acquire memory for writing these information. (Step (5)). The memory management function 814 acquires the requested memory area on the memory (step (6)). Thereafter, the page interpretation function 812 writes layout information and character information on the memory (step (7)).

 [0059] Next, as shown in FIG. 14, when image # 1 embedded in page # 3 is acquired (step (8)), cache function 811 requests memory management function 814 to acquire memory ( Step (9)), the memory management function 814 acquires the requested memory area on the memory (Step (10)). If the memory acquisition is successful, the cache function 811 caches the original data of image # 1 in the memory (step (11)).

 On the other hand, the image expansion function 813 requests the memory management function 814 to acquire memory in order to decode the image file of image # 1 (step (12)). In accordance with this request, the memory management function 814 tries to acquire a necessary memory area in a free area in the memory (step (13)). However, in this example, since the free space is not sufficient, the memory management function 814 fails to acquire memory (step (14)). Accordingly, the memory management function 814 determines and discards the image # 1 information that is a part of the display information of the currently inactive page # 1 (step (15)). This frees up memory for image # 1 and increases the free space. Disposing part of the page display information and expanding the free space is called “first release” of memory.

 Thereafter, as shown in FIG. 15, the memory management function 814 tries again to acquire a memory area for writing image # 1 information (step (16)), and succeeds (step (17)). ). The image expansion function 813 expands image # 1 of page # 3 and writes image # 1 information in the memory (step (18)).

[0062] Thus, according to the browser according to the present embodiment, when the memory area for writing information cannot be secured in the free area, the display information of inactive page # 1 (in this example, Layout information, text information, and image information) (in this example, image information as embedded information) is discarded to free up memory and free up space to free up memory for new page # 3. Secure and allow to open page # 3. [0063] In the "first release", a part of the page, in particular, layout information is left, and other information, in this example, the image is discarded. Therefore, when the user requests to open the page again. In other words, it is not necessary to execute all the processes from the beginning. For example, in the above example, when display of page # 1 is requested, it is possible to display page # 1 easily and quickly by recalling the original data of cached image # 1 and expanding it again. Is possible.

 [0064] In this example, the power of handling an image as information to be discarded among the display information of the page. In particular, other arbitrary objects such as audio and video embedded in the page are not limited to images. It may be data. Furthermore, layout information and text information may be used, but it is not very efficient because the HTML document needs to be interpreted again when the page is opened again. That is, one of the preferred aspects of the present invention is to leave the layout information and character information and discard the decoded data of the external object such as the image, moving image, and sound specified in the HTML document.

 Here, “inactive page” means an inactive page! /. An active page is usually the foremost page that is viewed and manipulated by the user. For example, in the example of the tab browser in FIG. 10, when a new page # 3 is opened, a page that is hidden by the active page # 3 and is not displayed is a non-active page. Therefore, in this example, both pages # 1 and # 2 are “inactive pages”. In the first memory release, when there are a plurality of inactive pages, there is no particular limitation on which page information is discarded depending on the setting. Further, a part of the information may be discarded from a plurality of inactive pages.

 [0066] Here, after actually writing page # 3HTML document, it is determined that there is no free space to write image # 1 information, but how much memory is available at the stage of interpreting page # 3HTML document? It may be determined or inferred whether it is necessary to determine whether the first memory release is necessary.

Next, a case where page # 3 further includes image # 2 will be described. As shown in FIG. 16, when the image expansion function 813 obtains the image file of image # 2 (step (19)), the cache function 811 requests the memory management function 814 to acquire the memory area necessary for the memory area. Then (step (20)), the memory management function 814 acquires the requested memory area on the memory (step (21)). If the memory acquisition is successful, the cache function 811 caches the original data of image # 2 in the memory (step (22)).

 [0068] Next, in order to decode this, the memory management function 814 is requested to acquire a memory of a necessary memory area (step (23)). In accordance with this request, the memory management function 814 tries to acquire a necessary memory area in a free area in the memory (step (24)). In this example, however, the memory management function 814 fails to acquire memory because there is not enough free space (step (25)). Therefore, the memory management function 814 confirms that there are no more images that can be discarded on page # 1, and then asks the user whether to close page # 1 (step (26)). ). If the user's consent is obtained, the memory management function 814 discards all information of page # 1, that is, cache information, layout information, and character information (step (27)). As a result, sufficient free space can be secured for writing image # 2 information. This is called “second free” of memory.

 [0069] Next, as shown in FIG. 17, the memory management function 814 tries to acquire the memory area for writing page # 3 image # 2 information again (step (28)), and succeeds (step (29)). The image expansion function 813 expands image # 2 and writes image # 2 information in the memory (step (30)).

 [0070] On the other hand, in the step (26) shown in FIG. 16, when the user confirms that the page # 1 is discarded, all information on the page # 1 is discarded. Cancels and the browser displays page # 3, the processed area, in this example text and image # 1.

 [0071] Of course, before deleting all the information on page # 1, the image # 1 information and image # 2 information on page # 2 may be discarded.

[0072] (Memory area management flowchart)

 FIG. 18 is a flowchart showing an example of memory area management processing of the browser memory management function 814 in the present embodiment.

[0073] When there is a request to open a page (Sl l, Yes), if the page is the first page (

S12, Yes), the maximum memory area of the browser information area 42 that can be used for the relevant page (S13). Here, “open page” means to display a new page that has not yet been displayed. That is, if you want to re-activate a page that has been opened but is inactive.

 In step S12, if the page to be opened is the second page or later, all the free areas in the maximum memory area are used for the page (S14). If this free space is insufficient (S15, Yes), the first memory release is executed and the page including the newly free space is used for the page (S16). If there is not enough free space (S17, Yes), the user is inquired whether the second memory release can be performed (S18). If the user's answer is OK (S19, Yes), the second memory release is executed and the new free area is used for the page (S20). If there is still not enough free space (S21, Yes), a message indicating that only the content is sufficient is output (S22), and such a display is performed. However, such message output is not essential.

 The present invention is most suitable for a browser program that operates on a wireless mobile terminal used in a wireless communication network such as a mobile phone network. In other words, in a wireless communication network, there is no guarantee that if the currently opened page is closed, it can be opened again if the communication environment changes frequently because the terminal moves. Therefore, by gradually releasing the memory to open a new page, the "first release" opens a new page while ensuring that inactive pages are displayed again (reproducibility) as much as possible. In the “second release”, the user's confirmation is canceled before all the information on the page is discarded, and if the page cannot be opened again, the user can cancel the page information destruction. It is possible to give an opportunity.

 [0076] Although a tab browser has been described as an example of a browser suitable for application of the present invention, the present invention is not limited to application to a tab browser! /.

 Industrial applicability

The present invention can be used for manufacturing and development of a browser program for browsing a markup language document and a markup language document processing apparatus.

Claims

The scope of the claims  [1] A memory area management method that uses a memory area for a new page opened in a device that executes a browser program that operates in an environment in which a fixed memory area is allocated to an application.  For a request to open a page, if that page is the first page opened first , Using the entire memory area allocatable to the page,  In response to a request to open another page while the first page is open, using the entire current free area of the allocatable memory area for the other page; and  When the memory area required by the other newly opened page is not enough, the memory area storing the embedded information embedded in the page among the memory areas to be used for the already opened page. Releasing step;  A step for using a free area including a released memory area for the newly opened page;  If there is not enough free space even if the memory area storing the embedded information is released, at least one page that has already been opened is used to release all the memory areas.  A memory area management method comprising:  [2] storing the markup language document constituting the page and the embedded information in a cache memory;  A step of reading and using the embedded information from the cache memory if the embedded information exists in the cache memory when reopening a page in which at least a part of the memory area is released;  The memory area management method according to claim 1, further comprising: [3] Before executing the step of releasing all the memory areas used by the at least one page that has already been opened, the method further comprises the step of asking the user of the device for permission to execute it. The memory area management method according to claim 1, wherein: [4] The browser program is opened in a single window opened on the display screen. 2. The memory area management method according to claim 1, wherein a number of pages are switched and displayed.  [5] A browser program that operates in an environment in which a fixed memory area is allocated to an application and has a function for using the memory area for the page to be opened. Is the first page opened first, the step of using the entire memory area allocatable to the page;  In response to a request to open another page while the first page is open, using the entire current free area of the allocatable memory area for the other page; and  When the memory area required by the other newly opened page is not enough, the memory area storing the embedded information embedded in the page among the memory areas to be used for the already opened page. Releasing step;  A step for using a free area including a released memory area for the newly opened page;  If there is not enough free space even if the memory area storing the embedded information is released, at least one page that has already been opened is used to release all the memory areas.  Browser program that executes.  [6] a step of storing a markup language document constituting a page and the embedded information in a cache memory;  A step of reading and using the embedded information from the cache memory if the embedded information exists in the cache memory when reopening a page in which at least a part of the memory area is released;  The browser program according to claim 5, further comprising: [7] Before executing the step of releasing all the memory areas used by the at least one page that has already been opened, the method further includes the step of asking the user of the device for permission to execute the step. The browser program according to claim 5, wherein [8] Switch multiple open pages in one window on the display screen. 6. The browser program according to claim 5, wherein the browser program is displayed. [9] A markup language document processing apparatus that executes a browser program that operates in an environment in which a fixed memory area is allocated to an application.  A communication unit for receiving a markup language document and embedded information embedded in the document; and  A storage unit for storing the received markup language document and embedded information; a display unit for analyzing the markup language document and displaying it together with the embedded information; and a new page to be opened in the memory area of the storage unit And a memory area management unit to be used for  The memory area management unit  For a request to open a page, if that page is the first page to be opened first, let the entire memory area allocatable to the page be used,  In response to a request to open another page while the first page is open, the entire current free area of the allocatable memory area is used for the other page,  When the memory area required by the other newly opened page is not enough, the memory area storing the embedded information embedded in the page among the memory areas to be used for the already opened page. Open,  If there is not enough free space even when the memory area storing the embedded information is released, all the memory areas that are already open and used by at least one page are released, and the free memory area A markup language document processing apparatus characterized in that a free area including a message is used for the newly opened page. [10] A markup language document constituting a page and a cache memory for storing the embedded information are provided, The memory area management unit reads out and uses the embedded information from the cache memory if the embedded information exists in the cache memory when reopening a page in which at least a part of the memory area is released. 10. The markup language document processing device according to claim 9, [11] Before executing the step of releasing all the memory areas used by the at least one page that has already been opened, the method further includes the step of asking the user of the device for permission to execute the step. 10. The markup language document processing device according to claim 9,  12. The markup language document processing apparatus according to claim 9, wherein the browser program switches and displays a plurality of opened pages in one window opened on a display screen.  13. The markup language document processing apparatus according to claim 9, wherein the communication unit includes a wireless network interface.