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#ifndef MERCURY_KERNEL_VFILE_HPP
#define MERCURY_KERNEL_VFILE_HPP
#include <mercury/kernel/storage.hpp>
#include <mercury/kernel/utility.hpp>
//TODO: mounts points.
//maybe a two-way map between mount points and targets? one mount point per
//target and vice versa. only directories may be mount points, and only file
//system roots (which must be directories) may be targets.
namespace mercury::kernel::vfile {
//a canon path contains no . or empty directory names, and
//contains no .. except for at the start of a relative path.
struct canon_path {
bool absolute;
unsigned parent_count;
utility::vector<utility::string> segments;
canon_path() : absolute(false), parent_count(0), segments(8) {}
void parent();
void rel(const canon_path &r);
utility::string to_string(bool trailing_slash) const;
};
void canonize_path(const utility::string &name, canon_path &out);
struct vfile {
//on followed symlinks, path is the source of the symlink and the
//rest of these are the target. in any case, path should be absolute.
canon_path path;
storage::block_device *bd;
storage::dir_entry dir_entry;
//TODO: instead of passing root, use saved mount points.
storage::fs_result follow_symlinks(
const vfile &root, std::optional<vfile> &out) const;
//dir_entry.type is assumed to be directory.
storage::fs_result get_child(
std::optional<vfile> &out, const utility::string &name) const;
//dir_entry.type is assumed to be directory. out must be empty on entry.
storage::fs_result get_children(utility::vector<vfile> &out) const;
//assumes file is a regular file and [start, start + length)
//is in bounds of file. start and length are in bytes.
storage::fs_result read_file(
uint64_t start, uint64_t length, void *into) const;
};
//path must be absolute. follows symlinks on all but the last node.
//relative_to should be a directory to do the lookup inside; e.g.,
//if relative_to is /a/b and path is c, then out becomes /a/b/c.
//TODO: instead of passing root, use saved mount points.
storage::fs_result lookup_path(
const vfile &root, const canon_path &path, std::optional<vfile> &out);
}
#endif
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