Verified Commit 4645fd16 authored by Tommaso Tocci's avatar Tommaso Tocci
Browse files

DB ops: get directory entries 

exposes a new  DB function that allows to retrieve all the
first-level entries of a specific directory.
parent b1c7f2bf

ifs/include/daemon/backend/metadata/db.hpp

+1 −0
Original line number Diff line number Diff line
@@ -26,6 +26,7 @@ class MetadataDB { 
        bool exists(const std::string& key);

        void update(const std::string& old_key, const std::string& new_key, const std::string& val);

        void update_size(const std::string& key, size_t size, bool append);

        std::vector<std::pair<std::string, bool>> get_dirents(const std::string& dir) const;

        void iterate_all();

};

ifs/src/daemon/backend/metadata/CMakeLists.txt

+1 −0
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ target_sources(metadata_db 
    ${INCLUDE_DIR}/daemon/backend/metadata/db.hpp

    ${INCLUDE_DIR}/daemon/backend/exceptions.hpp

    PRIVATE

    ${INCLUDE_DIR}/global/path_util.hpp

    ${INCLUDE_DIR}/daemon/backend/metadata/merge.hpp

    ${CMAKE_CURRENT_LIST_DIR}/merge.cpp

    ${CMAKE_CURRENT_LIST_DIR}/db.cpp

ifs/src/daemon/backend/metadata/db.cpp

+58 −0
Original line number Diff line number Diff line
@@ -2,6 +2,7 @@ 
#include <daemon/backend/metadata/merge.hpp>

#include <daemon/backend/exceptions.hpp>



#include <global/path_util.hpp>

#include <extern/spdlog/spdlog.h>



MetadataDB::MetadataDB(const std::string& path): path(path) {
@@ -44,6 +45,9 @@ std::string MetadataDB::get(const std::string& key) const { 
}



void MetadataDB::put(const std::string& key, const std::string& val) {

    assert(is_absolute_path(key));

    assert(key == "/" || !has_trailing_slash(key));



    auto cop = CreateOperand(val);

    auto s = db->Merge(write_opts, key, cop.serialize());

    if(!s.ok()){
@@ -97,6 +101,60 @@ void MetadataDB::update_size(const std::string& key, size_t size, bool append){ 
    }

}



/**

 * Return all the first-level entries of the directory @dir

 *

 * @return vector of pair <std::string name, bool is_dir>,

 *         where name is the name of the entries and is_dir

 *         is true in the case the entry is a directory.

 */

std::vector<std::pair<std::string, bool>> MetadataDB::get_dirents(const std::string& dir) const {

    auto root_path = dir;

    assert(is_absolute_path(root_path));

    //add trailing slash if missing

    if(!has_trailing_slash(root_path) && root_path.size() != 1) {

        //add trailing slash only if missing and is not the root_folder "/"

        root_path.push_back('/');

    }



    rocksdb::ReadOptions ropts;

    auto it = db->NewIterator(ropts);



    std::vector<std::pair<std::string, bool>> entries;



    for(it->Seek(root_path);

            it->Valid() &&

            it->key().starts_with(root_path) &&

            it->key().size() != root_path.size();

        it->Next()){



        /***** Get File name *****/

        auto name = it->key().ToString();

        if(name.find_first_of('/', root_path.size()) != std::string::npos){

            //skip stuff deeper then one level depth

            continue;

        }

        // remove prefix

        name = name.substr(root_path.size());



        //relative path of directory entries must not be empty

        assert(name.size() > 0);



        /***** Get File type *****/

        /*TODO: move this routine along with general metadata {de,se}rialization

         * functions

         */

        auto metadata = it->value().ToString();

        assert(metadata.size() > 0);

        auto mode = static_cast<mode_t>(stoul(metadata.substr(0, metadata.find(','))));

        auto is_dir = S_ISDIR(mode);



        entries.push_back(std::make_pair(std::move(name), std::move(is_dir)));

    }

    assert(it->status().ok());

    return entries;

}



void MetadataDB::iterate_all() {

    std::string key;

    std::string val;