Sovite.Core.Lookup behaviour (sovite v0.2.0)

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The interface routing uses to read Sovite's database tables (Sovite.Core.Repo.Tables.*): a key goes in, a string value or nothing comes out.

A table is {module, handle}, where module implements lookup/2. Routing holds tables as {name, table} pairs, so a failure can name the table.

Telemetry

  • [:sovite, :tables, :lookup_error] - %{}, %{table, reason}: a table could not be read; the mail is deferred or answered with a temporary error.

Summary

Types

result()

The result of a lookup: {:ok, value}, :error when the key is not in the table, or {:error, reason} when the table could not be read.

table()

A table: a module and its handle.

tables()

Named tables, searched in order.

Callbacks

lookup(handle, key)

Looks up key.

Functions

lookup(tables, keys)

Tries each key in turn, in each table, and returns the first value found with the key that found it. A table that cannot be read stops the search and returns {:error, name}: a later table must not answer for a key the failing one might hold.

Types

result()

@type result() :: {:ok, String.t()} | :error | {:error, term()}

The result of a lookup: {:ok, value}, :error when the key is not in the table, or {:error, reason} when the table could not be read.

table()

@type table() :: {module(), term()}

A table: a module and its handle.

tables()

@type tables() :: [{String.t(), table()}]

Named tables, searched in order.

Callbacks

lookup(handle, key)

@callback lookup(handle :: term(), key :: String.t()) :: result()

Looks up key.

Functions

lookup(tables, keys)

@spec lookup(tables(), [String.t()]) ::
  {:ok, String.t(), String.t()} | :error | {:error, String.t()}

Tries each key in turn, in each table, and returns the first value found with the key that found it. A table that cannot be read stops the search and returns {:error, name}: a later table must not answer for a key the failing one might hold.