An Efficient Access Method of Geographic Elements Based on Contiguous Memory

Abstract

The invention belongs to the technical field of data access, and is specifically a method for efficiently accessing geographic elements based on continuous memory, comprising the following steps: Step 1: Establishing a memory organization model, using 8-byte continuous units on the memory unit, because the equal size memory is easier to jump around and makes random access possible. In order to simplify the storage, refer to the Shapfile method, do not distinguish between multi-line (MultiLineString) and multi-polygon (MultiPolygon), the memory structure of the four types of elements is formed, and its structure is reasonable. This method can support fast access to major geographic element types, and supports Shapefile , PostGIS two mainstream geographic feature data external storage sources.

Description

technical field [0001] The invention relates to the technical field of data access, in particular to an efficient access method for geographic elements based on continuous memory. Background technique [0002] With the development of geographic information collection technology, the scale of geographic data continues to expand, requiring GIS algorithms to quickly access large-scale data. As an important type of geographic information, geographic element data plays an important role in the fields of land, geology, and hydrology. key role, these applications urgently need to improve the efficiency of geographic feature data access. [0003] The current mainstream access method of geographic element data is through object-oriented libraries such as OGR and ArcEngine. The characteristics of these access libraries are to disassemble geographic elements and their components into multiple layers and multiple small objects, and store them in memory. The creation and deletion of dat...

AI Technical Summary

Problems solved by technology

[0003] The current mainstream access method for geographic feature data is through object-oriented libraries such as OGR and ArcEngine. The creation and deletion of data access brings a high load on data access, which affects the performance of geographic feature data access. The time for simple traversal of geographic features is even several times that of reading data files from external memory.

Current feature formats based on continuous memory include WKB, FlatGeoBuf, etc. These formats are mainly for external memory storage, and often use different endianness from memory, requiring additional serialization / deserialization overhead. At the same time, because these formats usually use very compact The storage space is arranged, and the access program often needs to read linearly from the space, which cannot support effective parallel access

In actual use, these continuous memory-based types often only exist as external storage formats due to difficult access, and still need to be converted into multi-layer and multiple small objects in use, which cannot solve the aforementioned performance problems

[0004] Therefore, it is necessary to propose a method for accessing geographical elements based on continuous memory, which can overcome the performance problems caused by a large number of small objects and provide a fast and friendly access interface.

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