analytics/lib/plausible/site/cache.ex

105 lines
2.5 KiB
Elixir

defmodule Plausible.Site.Cache do
@moduledoc """
The cache allows lookups by both `domain` and `domain_changed_from`
fields - this is to allow traffic from sites whose domains changed within a certain
grace period (see: `Plausible.Site.Transfer`).
To differentiate cached Site structs from those retrieved directly from the
database, a virtual schema field `from_cache?: true` is set.
This indicates the `Plausible.Site` struct is incomplete in comparison to its
database counterpart -- to spare bandwidth and query execution time,
only selected database columns are retrieved and cached.
The `@cached_schema_fields` attribute defines the list of DB columns
queried on each cache refresh.
Also see tests for more comprehensive examples.
"""
require Logger
import Ecto.Query
alias Plausible.Site
use Plausible.Cache
@cache_name :sites_by_domain
@cached_schema_fields ~w(
id
domain
domain_changed_from
ingest_rate_limit_scale_seconds
ingest_rate_limit_threshold
)a
@impl true
def name(), do: @cache_name
@impl true
def child_id(), do: :cache_sites
@impl true
def count_all() do
from(s in Site.regular())
|> Plausible.Repo.aggregate(:count)
end
@impl true
def base_db_query() do
from s in Site.regular(),
left_join: rg in assoc(s, :revenue_goals),
inner_join: team in assoc(s, :team),
select: {
s.domain,
s.domain_changed_from,
%{struct(s, ^@cached_schema_fields) | from_cache?: true}
},
preload: [revenue_goals: rg, team: team]
end
@impl true
def get_from_source(domain) do
query = from s in base_db_query(), where: s.domain == ^domain
case Plausible.Repo.one(query) do
{_, _, site = %Site{}} -> %Site{site | from_cache?: false}
_any -> nil
end
end
@spec get_site_id(String.t(), Keyword.t()) :: pos_integer() | nil
def get_site_id(domain, opts \\ []) do
case get(domain, opts) do
%{id: site_id} ->
site_id
nil ->
nil
end
end
@spec touch_site!(Site.t(), DateTime.t()) :: Site.t()
def touch_site!(site, now) do
now =
now
|> DateTime.truncate(:second)
|> DateTime.to_naive()
site
|> Ecto.Changeset.change(updated_at: now)
|> Plausible.Repo.update!()
end
@impl true
def unwrap_cache_keys(items) do
Enum.reduce(items, [], fn
{domain, nil, object}, acc ->
[{domain, object} | acc]
{domain, domain_changed_from, object}, acc ->
[{domain, object}, {domain_changed_from, object} | acc]
end)
end
end