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447 righe
13 KiB
447 righe
13 KiB
#pragma once
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#include "gp/containers/array.hpp"
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#include <cstddef>
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#include <cstdint>
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// TODO: File locking and fsync/fdatasync
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namespace gp {
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/**
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* @brief this enum represents the types of operations available
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*/
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enum class operation_type {
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version, ///< this operation queries properties of the filesystem
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flush, ///< flushes any buffer for writing on the filesystem
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attach, ///< adds a filesystem to the system
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detach, ///< remove a filesystem from the system
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walk, ///< change the current directory
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create, ///< creates a file
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open, ///< opens a file, yielding a fid
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read, ///< reads from a file
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write, ///< writes to a file
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clunk, ///< relinquishes a fid
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remove, ///< removes a file
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stat, ///< reads a file metadata
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wstat ///< writes a file metadata
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};
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/**
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* @brief this enum represent the type of file handled
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*/
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enum class file_type {
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directory, ///< the file is a normal directory
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master_directory, ///< the file is the root directory of a non-root filesystem
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device_directory, ///< the file is a driver mapped to a directory
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root_directory, ///< the file is the root directory
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file, ///< the file is a normal file
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file_device, ///< the file is a driver mapped to a file
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message_pipe ///< the file is a channel to read and write messages to
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};
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/**
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* @brief represents file permissions
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*/
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struct permission_list {
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bool
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read : 1,
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write : 1,
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execute : 1;
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};
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/**
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* @brief represents all levels of permissions in a file
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*/
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struct file_permissions {
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permission_list
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user, ///< list of permissions for the owner
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group, ///< list of permissions for the owning group
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others; ///< list of permissions for other users
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};
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/**
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* @brief represent a value that should be unique for every entity of the system
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*/
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using unique_node = uint64_t;
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/**
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* @brief represent a timestamp in seconds
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*/
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using timestamp = uint64_t;
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/**
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* @brief represent a value that represent an offset into a file
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*/
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using file_offset = uint64_t;
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/**
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* @brief the expected return type of a stat query, as well as its writing counterpart
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*/
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struct f_stats {
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file_type type; ///< the type of file
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unique_node file_id; ///< the unique file id
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unique_node owner_user_id; ///< the user id of the owner of the file
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unique_node owner_group_id; ///< the group id of the file
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unique_node last_modifier_id; ///< the user id of the last user that wrote data to the file
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timestamp last_access; ///< the timestamp for the last time the file was opened or created. If the current user is not root, it is replaced by the system on wstat
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timestamp last_modification; ///< the last modification timestamp. If the current user is not root, it is replaced by the system on wstat
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file_offset file_size; ///< the filesize in bytes
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gp::array<char, 255> filename; ///< the filename, padded with null characters
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};
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/**
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* @brief Represent an IO operation as sent to the system, this is an abstract class.
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*/
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struct io_operation {
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const operation_type type; ///< the discriminant for the operation type
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protected:
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io_operation(operation_type a) : type(a) {}
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};
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/**
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* @brief This operation obtains the version of the targeted filesystem
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*/
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struct version_operation : public io_operation {
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const gp::buffer<char> destination; ///< the destination where the data is written
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const gp::buffer<char> root_path; ///< the path of the file system to query for version
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new version operation object
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*
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* @param dest the destination where the data is written
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* @param path the path to the target filesystem
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* @param v_fd a relative root that is used
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*/
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version_operation(
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gp::buffer<char> dest,
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gp::buffer<char> path,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::version}
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, destination(dest)
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, root_path(path)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation flushes a filesystem, writing the data to the associated medium
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*/
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struct flush_operation : public io_operation {
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const gp::buffer<char> root_path; ///< the path that is going to be flushed
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new flush operation object
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*
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* @param path the path to a file or to a master directory that is to be flushed
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* @param v_fd a relative root that is used
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*/
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flush_operation(
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gp::buffer<char> path,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::flush}
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, root_path(path)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation mounts a filesystem given a format and a configuration data.
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*
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* It also mounts devices.
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*/
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struct attach_operation : public io_operation {
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const gp::buffer<char> target_path; ///< location where the filesystem is going to be attached
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const gp::buffer<char> format; ///< format string of the filesystem
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const gp::buffer<char> configuration; ///< configuration data
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new attach operation object
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*
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* @param path path where the filesystem will be attached, must be either not existing or an empty directory
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* @param v_format the format name that will be invoked with the config
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* @param config the configuration to send
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* @param v_fd a relative root that is used
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*/
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attach_operation(
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gp::buffer<char> path,
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gp::buffer<char> v_format,
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gp::buffer<char> config,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::attach}
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, target_path(path)
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, format(v_format)
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, configuration(config)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation removes the master status of a directory and dismounts the
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* filesystem attached to it after flushing it. Will fail if any file is still attached
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* in the filesystem.
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*
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* This applies to the devices too.
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*/
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struct detach_operation : public io_operation {
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const gp::buffer<char> target_path; ///< the target master directory
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new detach operation object
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*
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* @param path the item to be detached
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* @param v_fd a relative root that is used
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*/
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detach_operation(
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gp::buffer<char> path,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::attach}
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, target_path(path)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation will move the focus of the target directory relative to itself or absolutely
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*/
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struct walk_operation : public io_operation {
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const gp::buffer<char> target_path; ///< the target to move to
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const gp_config::file_descriptor_t fd_to_alter; ///< the fd that will be modified
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/**
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* @brief Construct a new walk operation object
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*
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* @param path the target to move to
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* @param dir the original file descriptor
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*/
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walk_operation(
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gp::buffer<char> path,
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gp_config::file_descriptor_t dir
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)
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: io_operation{operation_type::walk}
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, target_path(path)
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, fd_to_alter(dir)
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{}
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};
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/**
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* @brief selector for the type of file to be created in a given environment
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*/
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enum class create_type {
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file, ///< normal file
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directory, ///< directory file
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temporary, ///< file which is to be remove upon all of his descriptors being closed
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pipe_read_side, ///< pipe, read side returned
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pipe_write_side ///< pipe, write side returned
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};
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/**
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* @brief This operation will attempt to create a file at the specified destination
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*/
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struct create_operation : public io_operation {
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const gp::buffer<char> target_path;
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const create_type mode;
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const gp::optional<gp_config::file_descriptor_t> fd;
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/**
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* @brief Create a new create operation object
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*
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* @param path the new file that is created
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* @param v_mode the type of file to create
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* @param v_fd a relative root that is used
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*/
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create_operation(
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gp::buffer<char> path,
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create_type v_mode,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::create}
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, target_path(path)
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, mode(v_mode)
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, fd(v_fd)
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{}
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};
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/**
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* @brief selector for the properties expected from an opened file descriptor
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*/
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enum class open_mode {
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read_only, ///< the descriptor will be read only, will fail if no read permissions
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read_write, ///< the descriptor is read-write, will fail if no write permissions, but not if no read permissions
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read_write_create ///< the descriptor is read-write, and has the same proterties as the read-write. The file will be created if it does not exist.
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};
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/**
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* @brief This operation will attempt to open a file at the specified destination
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*/
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struct open_operation : public io_operation {
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const gp::buffer<char> target_path; ///< the specified path
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open_mode mode; ///< the openning mode
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new open operation object
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*
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* @param path the path where to open a file
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* @param v_mode the mode of opening
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* @param v_fd a relative root that is used
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*/
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open_operation(
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gp::buffer<char> path,
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open_mode v_mode,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::create}
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, target_path(path)
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, mode(v_mode)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation will attempt to read a file into the destination starting at the specified offset in the file
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*/
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struct read_operation : public io_operation {
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const gp_config::file_descriptor_t fd; ///< the file to read
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const file_offset offset; ///< the offset to start reading at
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const gp::buffer<char> destination; ///< the destination where to write the data
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/**
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* @brief Construct a new read operation object
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*
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* @param v_fd the descriptor to read
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* @param off the offset to read
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* @param v_destination the location where the data will be written
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*/
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read_operation(
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gp_config::file_descriptor_t v_fd,
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file_offset off,
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gp::buffer<char> v_destination
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)
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: io_operation{operation_type::read}
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, fd{v_fd}
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, offset(off)
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, destination(v_destination)
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{}
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};
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/**
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* @brief This operation will attempt to write in file from the source starting at the specified offset in the file
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*/
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struct write_operation : public io_operation {
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const gp_config::file_descriptor_t fd; ///< the descriptor of the file where writing happens
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const file_offset offset; ///< the offset in the file where writing starts
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const gp::buffer<char> source; ///< the source data
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/**
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* @brief Construct a new write operation object
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*
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* @param v_fd the target file
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* @param off the target offset
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* @param v_source the data source buffer
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*/
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write_operation(
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gp_config::file_descriptor_t v_fd,
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file_offset off,
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gp::buffer<char> v_source
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)
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: io_operation{operation_type::write}
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, fd{v_fd}
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, offset(off)
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, source(v_source)
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{}
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};
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/**
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* @brief This operation closes a file by relinquishing its file descriptor
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*/
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struct clunk_operation : public io_operation {
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const gp_config::file_descriptor_t fd; ///< The descriptor that will be disposed of
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/**
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* @brief Construct a new clunk operation object
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*
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* @param v_fd the fd to close
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*/
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clunk_operation(gp_config::file_descriptor_t v_fd)
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: io_operation{operation_type::clunk}
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, fd{v_fd}
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{}
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};
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/**
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* @brief This operation removes a fileas soon as all its file descriptors are given back
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*/
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struct remove_operation : public io_operation {
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const gp::buffer<char*> target_path; ///< the target file
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new remove operation object
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*
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* @param path the path to the file to remove
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* @param v_fd a relative root that is used
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*/
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remove_operation(
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gp::buffer<char*> path,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::remove}
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, target_path(path)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation fetches metadata about a file
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*/
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struct stat_operation : public io_operation {
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const gp::buffer<char*> target_path; ///< the file to query metadata about
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new stat operation object
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*
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* @param path the path to the file to query about
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* @param v_fd a relative root that is used
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*/
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stat_operation(
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gp::buffer<char*> path,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::stat}
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, target_path(path)
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, fd(v_fd)
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{}
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};
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/**
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* @brief This operation writes metadata about a file
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*/
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struct wstat_operation : public io_operation {
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const gp::buffer<char*> target_path; ///< the file to set metadata on
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const gp::optional<gp_config::file_descriptor_t> fd; ///< the relative root to use
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/**
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* @brief Construct a new wstat operation object
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*
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* @param path the path to the file to write about
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* @param v_fd a relative root that is used
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*/
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wstat_operation(
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gp::buffer<char*> path,
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gp::optional<gp_config::file_descriptor_t> v_fd
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)
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: io_operation{operation_type::wstat}
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, target_path(path)
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, fd(v_fd)
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{}
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};
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}
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