Publishing messages based on geographic area

A method for publishing messages within a geographic area, the method comprising;

• receiving a location from each of a plurality of user devices;
• creating a geo-hash tree based on the location of each of a plurality of user devices;
• receiving a message with the geographic area, wherein the geographic area is non-rectangular;
• computing a geo-hash grid for a region that includes the geographic area, wherein the region includes an entirety of the geographic area and one or more areas that are not within the geographic area;
• identifying one or more nodes of the geo-hash tree that correspond to the geo-hash grid as candidate nodes;
• performing a point in a polygon algorithm for each of the candidate nodes to determine whether each of the one or more of the plurality of user devices associated with the candidate nodes are located inside or outside a boundary of the geographic area;
• and
• transmitting the message to one or more of the plurality of user devices associated with the candidate nodes that are determined to be located inside the geographic area.