Dynamically determining a tile budget when pre-fetching data in a client device

摘要

A pre-fetching map data system and method identifies a subset of map data to corresponding to one or more points of interest to be displayed on the map. The map data is stored on a remote map database in map data tiles. The pre-fetching map data system identifies those map data tiles that correspond to the one or more points of interest, where the identified pre-fetch map data tiles are sent from the remote database to a client device for cache storage. The number of pre-fetch map data tiles are determined using a tile budget that is dynamically adjusted in response to changing conditions on a client device.

主权项

1. A computer-implemented method comprising:
receiving an indication, at remote map database from a client device, of one or more map points of interest; identifying, based on the received indication, pre-fetch map data; determining a budget for storing the pre-fetch map data at the client device; receiving a request for the pre-fetch map data corresponding to one or more map points of interest; determining a change in availability of client device memory or network bandwidth; in response to determining the change in availability of memory or network bandwidth, dynamically adjusting the budget for storing the pre-fetch map data at the client device during receipt of the pre-fetch map data at the client device; and determining if the request for the pre-fetch map data meets the budget; when the budget has not been met, sending pre-fetch map data until the budget is met or until all pre-fetch map data corresponding to the one or more map points of interest have been received at the client device; and storing the received pre-fetch map data in a local memory on the client device until a subsequent user request.