mirror of
https://github.com/fish-shell/fish-shell
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82 lines
2.6 KiB
C++
82 lines
2.6 KiB
C++
#ifndef FISH_HISTORY_FILE_H
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#define FISH_HISTORY_FILE_H
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#include "config.h" // IWYU pragma: keep
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#include <sys/mman.h>
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#include <ctime>
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#include <memory>
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#include <string>
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#include "common.h"
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#include "maybe.h"
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class history_item_t;
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// History file types.
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enum history_file_type_t { history_type_fish_2_0, history_type_fish_1_x };
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/// history_file_contents_t holds the read-only contents of a file.
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class history_file_contents_t : noncopyable_t, nonmovable_t {
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public:
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/// Construct a history file contents from a file descriptor. The file descriptor is not closed.
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static std::unique_ptr<history_file_contents_t> create(int fd);
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/// Decode an item at a given offset.
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history_item_t decode_item(size_t offset) const;
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/// Support for iterating item offsets.
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/// The cursor should initially be 0.
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/// If cutoff is nonzero, skip items whose timestamp is newer than cutoff.
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/// \return the offset of the next item, or none() on end.
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maybe_t<size_t> offset_of_next_item(size_t *cursor, time_t cutoff) const;
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/// Get the file type.
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history_file_type_t type() const { return type_; }
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/// Get the size of the contents.
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size_t length() const { return length_; }
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/// Return a pointer to the beginning.
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const char *begin() const { return address_at(0); }
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/// Return a pointer to one-past-the-end.
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const char *end() const { return address_at(length_); }
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/// Access the address at a given offset.
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const char *address_at(size_t offset) const {
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assert(offset <= length_ && "Invalid offset");
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return start_ + offset;
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}
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~history_file_contents_t();
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private:
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// A type wrapping up the logic around mmap and munmap.
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struct mmap_region_t;
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const std::unique_ptr<mmap_region_t> region_;
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// The memory mapped pointer and length.
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// The ptr aliases our region. The length may be slightly smaller, if there is a trailing
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// incomplete history item.
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const char *const start_;
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const size_t length_;
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// The type of the mapped file.
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// This is set at construction and not changed after.
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history_file_type_t type_{};
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// Private constructors; use the static create() function.
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explicit history_file_contents_t(std::unique_ptr<mmap_region_t> region);
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history_file_contents_t(const char *start, size_t length);
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// Try to infer the file type to populate type_.
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// \return true on success, false on error.
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bool infer_file_type();
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};
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/// Append a history item to a buffer, in preparation for outputting it to the history file.
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void append_history_item_to_buffer(const history_item_t &item, std::string *buffer);
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#endif
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