llfio_v2_xxx::algorithm::compare_visitor Struct Reference

A visitor for the filesystem traversal and comparison algorithm. More...

#include "difference.hpp"

Inheritance diagram for llfio_v2_xxx::algorithm::compare_visitor:

Public Member Functions
virtual result< void >	post_enumeration (void *data, const directory_handle &dirh, directory_handle::buffers_type &contents, size_t depth) noexcept override
	This override implements the summary.
virtual result< directory_handle >	directory_open_failed (void *data, result< void >::error_type &&error, const directory_handle &dirh, path_view leaf, size_t depth) noexcept override
	This override ignores failures to traverse into the directory.
virtual result< bool >	pre_enumeration (void *data, const directory_handle &dirh, size_t depth) noexcept
	Called to decide whether to enumerate a directory. More...
virtual result< void >	stack_updated (void *data, size_t dirs_processed, size_t known_dirs_remaining, size_t depth_processed, size_t known_depth_remaining) noexcept
	Called whenever the traversed stack of directory hierarchy is updated. This can act as an estimated progress indicator, or to give an accurate progress indicator by matching it against a previous traversal. More...
virtual result< size_t >	finished (void *data, result< size_t > result) noexcept
	Called when a traversal finishes, whether due to success or failure. Always called from the original thread.

Static Public Member Functions
static void	accumulate (comparison_summary &acc, comparison_summary *state, const directory_handle *dirh, directory_entry &entry, stat_t::want already_have_metadata)
static void	accumulate (traversal_summary &acc, traversal_summary *state, const directory_handle *dirh, directory_entry &entry, stat_t::want already_have_metadata)

Detailed Description

A visitor for the filesystem traversal and comparison algorithm.

Note that at any time, returning a failure causes compare() to exit as soon as possible with the same failure.

You can override the members here inherited from traverse_visitor, however note that compare() is entirely implemented using traverse(), so not calling the implementations here will affect operation.

Member Function Documentation

pre_enumeration()

virtual result<bool> llfio_v2_xxx::algorithm::traverse_visitor::pre_enumeration ( void *  data, const directory_handle &  dirh, size_t  depth  )

inlinevirtualnoexceptinherited

Called to decide whether to enumerate a directory.

Note that it is more efficient to ignore the directory entry in post_enumeration() than to ignore it here, as a handle is opened for the directory before this callback. Equally, if you need that handle to inspect the directory e.g. to check if one is entering a different filesystem from the root, here is best.

The default returns true.

Note

May be called from multiple kernel threads concurrently.

    {
      (void) data;
      (void) dirh;
      (void) depth;
      return true;
    }

stack_updated()

virtual result<void> llfio_v2_xxx::algorithm::traverse_visitor::stack_updated ( void *  data, size_t  dirs_processed, size_t  known_dirs_remaining, size_t  depth_processed, size_t  known_depth_remaining  )

inlinevirtualnoexceptinherited

Called whenever the traversed stack of directory hierarchy is updated. This can act as an estimated progress indicator, or to give an accurate progress indicator by matching it against a previous traversal.

Parameters

data	The third party data pointer passed to traverse().
dirs_processed	The total number of directories traversed so far.
known_dirs_remaining	The currently known number of directories awaiting traversal.
depth_processed	How many levels deep we have already completely traversed.
known_depth_remaining	The currently known number of levels we shall traverse.

Note

May be called from multiple kernel threads concurrently.

    {
      (void) data;
      (void) dirs_processed;
      (void) known_dirs_remaining;
      (void) depth_processed;
      (void) known_depth_remaining;
      return success();
    }

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The documentation for this struct was generated from the following file:

• include/llfio/v2.0/algorithm/difference.hpp