WO2001042923A2

WO2001042923A2 - Method for the storage of data in a file on a data storage device

Info

Publication number: WO2001042923A2
Application number: PCT/EP2000/011847
Authority: WO
Inventors: Christian Rutkowski; Hans Schwab
Original assignee: Dr. Johannes Heidenhain Gmbh
Priority date: 1999-12-08
Filing date: 2000-11-28
Publication date: 2001-06-14
Also published as: WO2001042923A3; EP1259884A2; DE19960114A1

Abstract

The invention relates to a method for the storage of data in a file on a data storage device, comprising a working memory (2), which is directly dedicated to a microprocessor (1) and in which data, necessary for the execution of data processing programs, by the microprocessor (1), is stored. Said device further comprises a mass memory (4, 5), for the storage of further data, whereby the data is stored in at least two different fragments (F, F1 - F5) of the file, which are arranged in different areas of the data storage device and whereby a reference list (Z) is generated, in which the arrangement of file fragments (F, F1 - F5), in different regions of the data storage device, is stored. According to the invention, the data is at least partly stored in file fragments (F, F1 - F5) in the mass memory (4, 5) and the entries in the reference list (Z) are stored in the working memory (2).

Description

Method for storing data in a file of a data storage system

The invention relates to a method for storing data in a file of a data storage system according to the preamble of claim 1, wherein the data storage system comprises at least one working memory and an additional mass storage device.

A working or main memory is understood to mean a memory in a digital computing system with which the processor of the computing system cooperates directly and which contains program instructions, data and intermediate results which are required by the processor when executing a data processing program. Additional external storage, e.g. understood in the form of floppy disks or hard disks that provide additional storage space for data.

As a rule, the processor's access time to the data stored in the main memory or main memory is considerably shorter than the access time to data in the mass storage device, so that there is an attempt to access only such data or to process only such data when a program is executed need to be stored in the working memory. It is therefore customary, during the course of a data processing program, to store such files in the working memory, the data of which the processor accesses when the program commands are executed or whose content has to be changed continuously. However, the size of the available files is limited by the memory capacity of the working memory.

In cases in which the storage requirement of the required files exceeds the storage capacity of the available working memory, it may be necessary to access files or files by changing their content when executing a data processing program to process that are not in the working memory at this time, but in an additional, external memory, such as a floppy disk or a hard disk.

For this purpose, it is known, when inserting a data record into a file which is stored in a mass storage device, to temporarily save the parts of the file which are behind the insertion position for the new data record in a separate, separate file. The data record to be inserted is then added after the insertion position and the data temporarily stored in the temporary file is appended to the new data record. Correspondingly, a data record is deleted from a file.

This method of inserting a data record into a file or deleting a data record in a file has the disadvantage that, due to the plurality of work steps that have to be carried out when the file is edited in a mass storage device, too much time is required to edit the file , This applies in particular if the file stored in the mass storage device is accessed via a network.

The aforementioned method for inserting or deleting a data record in a file can therefore not be used in cases in which there is very little time available for processing files. An example of this are numerically controlled machines, in particular machine tools, the processors of which have to process complex, time-consuming algorithms for the positioning of individual machine parts and for which therefore only little computing time is required to enter the data required to execute the corresponding data processing programs, such as the actual and target positions of machine parts is available.

These disadvantages also exist in another known method for inserting a data record into a file stored on a mass storage device, in which the data before the insertion position of the new data tes set file content is saved in a separate file. The data record to be inserted and the remnants of the original file are then added to this new file one after the other. A data record is deleted in a corresponding manner, the data record to be deleted not being written into the new file.

The invention has for its object to provide a method for storing data in a file of a data storage system of the type mentioned, in which the computing times required for processing the file, in particular the computing times required for inserting or deleting data records, are minimized ,

According to the invention, this object is achieved by a method having the features of claim 1.

The data is then stored in a file which consists of at least two file fragments, which are assigned to different physical areas of the data storage system and at least one of which is stored in a mass storage device, and an assignment list is created in the working memory of the data storage system, in which stores the assignment of the file fragments to the different areas of the data storage system.

The invention is based on the knowledge that the known division of a file into several file fragments, the distribution of which over different, spatially spaced (spatially non-contiguous) areas of a data memory is noted in an assignment list (also called a file assignment table) (compare e.g. H.-P. Messmer, PC hardware book, 3rd edition, Bonn, 1995, pp. 738 - 760), can be expanded in such a way that the file fragments on the one hand and the assignment list on the other hand in different memories of a data storage system (namely in a mass storage device on the one hand and a working memory on the other hand) are provided. By dividing a file into different file fragments, each of which only contains part of the content of the entire file, the processing of a file can be considerably simplified, in particular with regard to the addition or deletion of data records. It is no longer necessary to first split the file into parts by several copying processes, then add or delete data in the individual parts of the file and then reassemble the file into one unit. Rather, the addition or deletion of data can be done in a simple manner by creating new file fragments, as will be explained in more detail below with the aid of advantageous developments of the invention.

Before editing a file, it can consist of only one file fragment (stored in a contiguous memory area). The file is then divided into several file fragments only when the file is edited by adding or deleting individual data records.

The changes in the number and / or content of the file fragments that occur when adding or deleting data records are taken into account in each case by corresponding entries in the assignment list, so that all the data in the file can be accessed at any time using the current assignment list.

In the context of the invention, it is of particular importance that the assignment list is stored in the working memory, while the file fragments are at least partially (i.e. at least one file fragment) stored outside the working memory in an additional, external mass storage device (such as a floppy disk or a hard disk) are. Of course, the individual file fragments can also be stored completely in the mass storage device.

Due to the at least partial storage of the file fragments in an additional mass storage device, the size of the file is not determined by the Memory capacity limited. By means of the assignment list, which is stored in the main memory or memory directly assigned to the processor and whose entries refer to the individual file fragments (ie contain the assignment of the file fragments to certain physical areas of a memory), it is possible at any time to refer to those in the individual file fragments stored data can be accessed, with access to the assignment list itself requiring very little computing time.

As a result, the solution according to the invention enables faster processing of files that are stored in a separate working memory due to the limited memory capacity of the main memory of the computing system and thus improves the functionality of the data storage system and the overall computing system.

In the context of the method according to the invention, the addition of a data record to a file can be carried out in a simple manner by storing the data record in a separate file fragment and adding an entry to the assignment list which refers to this additional file fragment, that is to say the assignment of this Contains file fragments to a specific area of a data storage.

If you want to add a data record to a file by inserting this data record into an existing file fragment, then this file fragment is first divided into two partial fragments (which in turn are file fragments) by a separate entry for each of the two partial fragments is created in the assignment list, which refers to the corresponding partial fragment. A file fragment is therefore easily divided into two smaller file fragments (referred to here as partial fragments) by merely modifying the entries in the memory assignment list accordingly. No changes need to be made to the file fragment itself. The two entries in the assignment list that refer to the partial fragments can be formed by referring to the original entry is copied and then the original entry and its copy are modified to adapt to the division of the file fragment into two partial fragments.

After dividing the file fragment into two partial fragments by modifying the assignment list accordingly, an entry is added to the assignment list which refers to the additional file fragment which contains the data record to be inserted. The individual entries in the assignment list must either be arranged in such a way or linked (by references) that the added file fragment is assigned the correct position within the file (i.e. between the two partial fragments that formed the original file fragment).

When a data record is appended to the beginning or end of a file fragment, it is simply expanded to include the data record to be added and the entry referring to the file fragment is modified accordingly.

To delete a data record of a file fragment in the context of the method according to the invention, at least one entry is formed in the assignment list which refers to the partial fragment (s) of the file fragment still remaining after the data record has been deleted. Deleting a data record in a file therefore only requires changing the entries in the assignment list stored in the working memory; the actual content of the file is not changed.

It should be pointed out again here that the file fragment in which a data record is to be deleted can be identical to the entire file. In such a case, the file is not divided into several file fragments until the first-mentioned file fragment is divided into several smaller file fragments (partial fragments) while the data record is being deleted. If a data record is to be deleted that is neither stored at the beginning nor at the end of a file fragment, the file fragment is divided into two partial fragments containing the data that are not to be deleted, by creating a separate entry in the assignment list for each of the two partial fragments the corresponding partial fragment refers. The two new entries in the assignment list can be formed in a simple manner by copying the entry referring to the original file fragment and then modifying it in a suitable manner.

When deleting a data record that is stored at the beginning or at the end of a file fragment, an entry is formed in the assignment list that refers to the remaining part of the file fragment. To completely delete a file fragment, the associated entry in the assignment list is simply deleted.

A data record of a file is overwritten by a combination of the above-described method steps "deleting a data record" and "adding a data record".

The assignment of the file fragments to different areas of a data memory by means of the assignment list preferably takes place in that each entry of the assignment list has a reference to the beginning and the end of the storage area occupied by the respective file fragment.

The entries in the assignment list do not have to be arranged consecutively; rather, each entry in the assignment list can also contain a reference to the subsequent entry. The entries in the assignment list are thereby linked to one another, even if they are not stored in the main memory in a spatially contiguous manner. The application of the method according to the invention for storing data to a method for the numerical control of machines, in particular machine tools, is characterized by the features of claim 14.

A data storage system which comprises a working memory and at least one additional mass storage device and in which data are stored in a manner corresponding to the method according to the invention is characterized by the features of claim 15.

Further advantages of the invention will become clear in the following description of an embodiment with reference to the figures.

Show it

Figure 1 is a schematic representation of a data storage system which is integrated in a computing system;

2a and 2b show a schematic representation of two processing steps when inserting a data record into a file;

FIGS. 3a and 3b show a schematic representation of two work steps when deleting a data record in a file.

In FIG. 1, a computing system is shown schematically in a block diagram, which has as its central components a microprocessor 1 and a main memory 2 directly assigned to the microprocessor 1. The program instructions required for executing a data processing program, the required data, and intermediate and final results are stored in the working memory 2. In addition, mass storage devices 4, 5 are connected to the microprocessor 1 via a controller 3, which can be, for example, a floppy disk in a floppy disk drive or a hard disk of a hard disk drive. Larger amounts of data can be read in there and possibly permanently saved, for which the capacity of the main memory 2 is not sufficient. The main memory 2 is, however, distinguished from the mass memories 4, 5 by the fact that the access time of the microprocessor 1 to the main memory 2 is considerably shorter than to the mass memories 4, 5.

Furthermore, an input / output device 8 is connected to the microprocessor 1, via which the computer system 1 can be connected to external devices such as e.g. a control panel, a screen and a control device for machine tools can be connected.

When using the computer system shown in FIG. 1 in a numerical control for machine tools, it is necessary to store large amounts of data, for example the actual and target data, in the data storage system of the computer system, which includes the main memory 2 and the two mass memories 4, 5 -Positions of machine parts of the machine to be controlled. Because of the limited capacity of the main memory, it is therefore often necessary to store at least some of the data required for control purposes in files which are stored in one of the mass memories 4, 5.

On the basis of FIGS. 2 and 3, it will now be explained how the processing of files which are stored on one of the mass memories 4, 5 can be carried out with a minimum of computing time.

FIG. 2a shows a file consisting of a single file fragment F, which is stored in one of the mass memories 4, 5 and occupies the memory space available between an address A1 (beginning of the file fragment) and an address A2 (end of the file fragment) , This file fragment F is an entry in an in the ar- beitsspeicher 2 assigned assignment list Z, which refers to this file fragment F and this addresses A1 and A2.

If an additional data record is to be inserted into the file fragment F, the file fragment F is divided into two partial fragments F1 and F2 according to FIG. 2b, each of which forms a smaller file fragment and between which the additional data record is to be inserted. This is done by creating two new entries in the assignment list Z by first copying the previous entry and then modifying both the previous entry and its copy. The two current entries in the assignment list Z then each refer to one of the two file fragments F1, F2, one entry assigning the addresses A1, A4 to the first file fragment F1, which designate the beginning and end of the memory area occupied by this file fragment F1, and the other entry assigns the addresses A3, A2 to the second file fragment F2, which designate the beginning and the end of the storage space occupied by that file fragment F2.

The additional data record is stored in a separate file fragment F3 on one of the mass memories 4, 5, specifically in a memory area identified by the addresses A5, A6. A third entry in the assignment list Z refers to this file fragment F3, which assigns the addresses A5, A6 in the corresponding mass memory 4 or 5 to the file fragment F3.

To insert a data record into a file F, it is therefore only necessary to save this data record at any position in one of the mass memories 4, 5 and then to carry out some modifications in the assignment list Z stored in the main memory. This minimizes the computing time required to insert a data record into a file.

The individual entries in the assignment list Z do not have to be arranged in succession, as shown in FIG. 2b. The arrangement of the entries in the assignment list Z is rather arbitrary, provided that each of these entries additionally contains a reference to the following entry.

To delete a data record in a file fragment F, according to FIGS. 3a and 3b, the file fragment F is divided into two partial fragments F4, F5, one of which contains the file content lying in front of the data record G to be deleted and the other the one behind the data record G to be deleted Contains file content. The subdivision of the file fragment F into two sub-fragments F4, F5 takes place in that (in the same way as already explained with reference to FIGS. 2a and 2b) two entries are formed in the assignment list Z, one of which on the first sub-fragment F4 and the one others refer to the second partial fragment F5. The one entry assigns the first sub-fragment F4 the addresses A1, A8, which represent the beginning and the end of the memory space occupied by this file fragment; and the other entry correspondingly assigns addresses A7, A2 to the second file fragment F5. The deleted data record G is therefore located in an area of the mass storage device 4 or 5 to which none of the entries in the assignment list Z refers.

It is clear that a data record is deleted in a simple manner by modifying the assignment list Z stored in the main memory. This minimizes the computing time required when deleting a data record.

Of course - in a modification of the exemplary embodiment illustrated with reference to FIGS. 2 and 3 - the file, which in each case represents the starting point for inserting or deleting a data record, can also consist of several file fragments even before these operations begin.

If necessary, the file generated by means of the method according to the invention when inserting or deleting a data record and consisting of several separate file fragments can be combined again to form a uniform file stored in a contiguous memory area. be caught. For this purpose, the individual file fragments are stored in succession in a file to which a contiguous storage area is assigned. The order of the arrangement of the individual file fragments is clearly determined by the assignment list, be it by the order of the arrangement of the entries in the assignment list or by references in the individual entries of the assignment list, each of which refers to the following entry. This combination of the individual file fragments into a file arranged in a coherent memory area can take place at a suitable point in time at which sufficient computing time is available for this operation.

Claims

claims

1. A method for storing data in a file of a data storage system which comprises a working memory (2) which is directly assigned to a microprocessor (1), and a mass storage device (4, 5) which is provided for storing further data, the Data are stored in at least two different fragments (F, F1 - F5) of the file, which are assigned to separate areas of the data storage system, and wherein an assignment list (Z) is formed in which the assignment of the file fragments (F, F1 - F5) to different areas of the data storage system is stored, characterized in that at least one of the file fragments (F,

F1 - F5) is stored in the mass memory (4, 5) and that the entries in the assignment list (Z) are stored in the main memory (2).

2. The method according to claim 1, characterized in that for adding a data record to a file, the data record is stored in a separate file fragment (F3) and an entry is added to the assignment list (Z) which refers to the file fragment (F3).

3. The method according to claim 2, characterized in that for inserting a data record in a file fragment (F), the file fragment is divided into two partial fragments (F1, F2) by a separate entry in the for each of the two partial fragments (F1, F2) Assignment list (Z) is formed, which refers to the corresponding partial fragment (F1, F2).

4. The method according to claim 3, characterized in that the two entries in the assignment list (Z) are formed by copying the entry referring to the original file fragment (F) and then modifying it.

5. The method according to claim 1, characterized in that when a data record is attached to a file fragment (F), the file fragment is expanded by this data record and the entry of the assignment list (Z) referring to the file fragment is modified.

6. The method according to any one of claims 1 to 5, characterized in that for deleting a data record (G) of a file fragment (F) at least one entry in the assignment list (Z) is formed, which refers to at least one remaining partial fragment (F4 , F5) of the file fragment (F).

7. The method according to claim 6, characterized in that for deleting a data record (G) that is stored neither at the beginning nor at the end of the file fragment (F), the file fragment (F) into two partial fragments containing the data not to be deleted (F4 , F5) is divided by creating a separate entry in the assignment list (Z) for each of the two partial fragments (F4, F5), which refers to the corresponding partial fragment (F4, F5).

8. The method according to claim 7, characterized in that the two entries in the assignment list (Z) are formed by copying the entry referring to the original file fragment (F) and then modifying it.

9. The method according to claim 6, characterized in that for deleting a data record which is stored at the beginning or at the end of the file fragment (F), an entry is formed in the assignment list (Z) which refers to the remaining partial fragment of the file fragment.

10. The method according to any one of claims 1 to 5, characterized in that in order to completely delete a file fragment (F), the associated entry in the assignment list (Z) is deleted.

11. The method according to any one of the preceding claims, characterized in that to overwrite a data record of a file, the data record is deleted and then a new data record is inserted at the corresponding point in the file.

12. The method according to any one of the preceding claims, characterized in that each entry of the assignment list (Z) a reference to the start (A, A3, A5, A7) and the end (A2, A4, A6, A8) of the respective Contains file fragment (F, F1 - F5) occupied memory area.

13. The method according to any one of the preceding claims, characterized in that each entry of the assignment list (Z) contains a reference to the subsequent entry.

14.Method for controlling and / or regulating machines, in particular machine tools, using a microprocessor (1) and a data storage system which comprises a working memory (2) which is directly assigned to the microprocessor (1), and a mass storage device (4 , 5), which is provided for storing further data, with data being stored in the data storage system according to one of the preceding claims.

5. Data storage / stem, which comprises a working memory (2), which is directly assigned to a microprocessor (1), and a mass storage device (4, 5), which is provided for storing further data, with at least one group of data in the data storage system is stored in a file, the data being stored in at least two different fragments (F, F1-F5) of the file, which are assigned to separate areas of the data storage system, and an assignment list (Z) is provided in which the assignment of the file fragments is provided (F, F1 - F5) is stored for different areas of the data storage system, characterized in that at least one of the file fragments (F, F1 - F5) is stored in the mass storage device (4, 5) and that the entries in the assignment list (Z ) are stored in the main memory (2).