View Source EchoPubSub.Producer.RingBuffer (EchoPubSub v0.2.4)

Pure helpers over the producer's fixed-size :array. Cursors only grow; a cursor maps to slot rem(cursor, capacity), so a write overwrites the message capacity positions behind it.

Summary

Types

cursor()
pending()
t()

Functions

capacity(buffer)

Number of messages the buffer holds.

new(size)

An empty buffer holding the last size messages.

pending(buffer, read_cursor, write_cursor)

What a node with read_cursor still needs: nothing, the messages up to write_cursor in order, or {:expired, missed} once the oldest missed were overwritten.

put(buffer, cursor, message)

Stores message at cursor, overwriting the slot's previous message.

Types

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cursor()

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@type cursor() :: non_neg_integer()
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pending()

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@type pending() :: :caught_up | {:expired, pos_integer()} | {:messages, [term()]}
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t()

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@type t() :: :array.array()

Functions

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capacity(buffer)

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@spec capacity(t()) :: pos_integer()

Number of messages the buffer holds.

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new(size)

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@spec new(pos_integer()) :: t()

An empty buffer holding the last size messages.

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pending(buffer, read_cursor, write_cursor)

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@spec pending(t(), cursor(), cursor()) :: pending()

What a node with read_cursor still needs: nothing, the messages up to write_cursor in order, or {:expired, missed} once the oldest missed were overwritten.

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put(buffer, cursor, message)

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@spec put(t(), cursor(), term()) :: t()

Stores message at cursor, overwriting the slot's previous message.