Minga.Buffer.SaveState (Minga v0.1.0)

Tracks whether a buffer has diverged from its last saved baseline.

This module owns the pure save-point model: mutation versions, the saved version, dirty calculation, and the saved file fingerprint used by persistence conflict checks. It does not read or write files; Minga.Buffer.Persistence still owns storage I/O.

Summary

Types

metadata()

saved_content_status()

t()

Functions

accept_saved_content(save_state, arg, content)

Accepts replacement content as a new saved baseline and allocates a unique revision.

acknowledge_disk_metadata(save_state, arg)

Acknowledges the latest disk metadata while preserving the saved content fingerprint.

changed_since_saved?(save_state, disk_mtime, disk_size, status)

Returns true when the backing file differs from the saved baseline.

content_fingerprint(content)

Fingerprints content with the algorithm used to track saved file baselines.

dirty?(save_state)

Returns whether the buffer differs from its saved version.

file_hash(save_state)

Returns the saved content fingerprint, if one is known.

file_size(save_state)

Returns the saved file size.

loaded(path, arg, content)

Returns a clean save state for content loaded from storage.

mark_changed(save_state)

Marks the buffer as changed and allocates a unique content revision.

mark_saved(save_state, arg, content)

Records the current version as the saved baseline.

mtime(save_state)

Returns the saved file mtime.

new()

Returns a clean save state for a new buffer with no saved file baseline.

record_clean_change(save_state)

Records a content change that should not by itself make a clean buffer dirty.

restore_version(save_state, version)

Restores a content revision and recalculates dirty state from the saved revision.

saved_content_fingerprint(path, mtime, content)

Returns a saved-content fingerprint only when a path and concrete mtime make the baseline meaningful.

saved_version(save_state)

Returns the saved baseline revision.

version(save_state)

Returns the current content revision.

Types

metadata()

@type metadata() :: {mtime :: integer() | nil, size :: non_neg_integer() | nil}

saved_content_status()

@type saved_content_status() :: :same | :changed | :unknown

t()

@opaque t()

Functions

accept_saved_content(save_state, arg, content)

@spec accept_saved_content(t(), metadata(), String.t()) :: t()

Accepts replacement content as a new saved baseline and allocates a unique revision.

acknowledge_disk_metadata(save_state, arg)

@spec acknowledge_disk_metadata(t(), metadata()) :: t()

Acknowledges the latest disk metadata while preserving the saved content fingerprint.

changed_since_saved?(save_state, disk_mtime, disk_size, status)

@spec changed_since_saved?(
  t(),
  integer() | nil,
  non_neg_integer() | nil,
  saved_content_status()
) :: boolean()

Returns true when the backing file differs from the saved baseline.

content_fingerprint(content)

@spec content_fingerprint(String.t()) :: binary()

Fingerprints content with the algorithm used to track saved file baselines.

dirty?(save_state)

@spec dirty?(t()) :: boolean()

Returns whether the buffer differs from its saved version.

file_hash(save_state)

@spec file_hash(t()) :: binary() | nil

Returns the saved content fingerprint, if one is known.

file_size(save_state)

@spec file_size(t()) :: non_neg_integer() | nil

Returns the saved file size.

loaded(path, arg, content)

@spec loaded(String.t() | nil, metadata(), String.t()) :: t()

Returns a clean save state for content loaded from storage.

mark_changed(save_state)

@spec mark_changed(t()) :: t()

Marks the buffer as changed and allocates a unique content revision.

mark_saved(save_state, arg, content)

@spec mark_saved(t(), metadata(), String.t()) :: t()

Records the current version as the saved baseline.

mtime(save_state)

@spec mtime(t()) :: integer() | nil

Returns the saved file mtime.

new()

@spec new() :: t()

Returns a clean save state for a new buffer with no saved file baseline.

record_clean_change(save_state)

@spec record_clean_change(t()) :: t()

Records a content change that should not by itself make a clean buffer dirty.

restore_version(save_state, version)

@spec restore_version(t(), non_neg_integer()) :: t()

Restores a content revision and recalculates dirty state from the saved revision.

saved_content_fingerprint(path, mtime, content)

@spec saved_content_fingerprint(String.t() | nil, integer() | nil, String.t()) ::
  binary() | nil

Returns a saved-content fingerprint only when a path and concrete mtime make the baseline meaningful.

saved_version(save_state)

@spec saved_version(t()) :: non_neg_integer()

Returns the saved baseline revision.

version(save_state)

@spec version(t()) :: non_neg_integer()

Returns the current content revision.