Graham McIntire
b08eba2c6b
Convert the packets table to a time-partitioned table with daily partitions (PARTITION BY RANGE on received_at). This replaces the expensive CTE-based batch DELETE cleanup with instant DROP TABLE partition drops — no dead tuples, no WAL pressure, no VACUUM needed. - Add PartitionManager GenServer to create/drop daily partitions - Simplify PacketCleanupWorker to delegate to PartitionManager - Replace gridsquare/geocalc deps with local Maidenhead module - Remove gettext_pseudolocalize dependency - Fix Decimal comparison in packet consumer test
33 lines
841 B
Elixir
33 lines
841 B
Elixir
defmodule Aprsme.Maidenhead do
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@moduledoc """
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Encodes longitude/latitude to Maidenhead grid square locators (6 characters).
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"""
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@spec encode(number() | nil, number() | nil) :: String.t() | nil
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def encode(lon, lat) when is_number(lon) and is_number(lat) do
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lon = lon + 180.0
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lat = lat + 90.0
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field_lon = trunc(lon / 20)
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field_lat = trunc(lat / 10)
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lon = lon - field_lon * 20
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lat = lat - field_lat * 10
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square_lon = trunc(lon / 2)
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square_lat = trunc(lat)
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lon = lon - square_lon * 2
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lat = lat - square_lat
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sub_lon = trunc(lon / (2 / 24))
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sub_lat = trunc(lat / (1 / 24))
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sub_lon = min(sub_lon, 23)
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sub_lat = min(sub_lat, 23)
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<<?A + field_lon, ?A + field_lat, ?0 + square_lon, ?0 + square_lat, ?a + sub_lon, ?a + sub_lat>>
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end
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def encode(_lon, _lat), do: nil
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end
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