1 /**

     2  * Relational pipes

     3  * Copyright © 2019 František Kučera (Frantovo.cz, GlobalCode.info)

     4  *

     5  * This program is free software: you can redistribute it and/or modify

     6  * it under the terms of the GNU General Public License as published by

     7  * the Free Software Foundation, version 3 of the License.

     8  *

     9  * This program is distributed in the hope that it will be useful,

    10  * but WITHOUT ANY WARRANTY; without even the implied warranty of

    11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

    12  * GNU General Public License for more details.

    13  *

    14  * You should have received a copy of the GNU General Public License

    15  * along with this program. If not, see <http://www.gnu.org/licenses/>.

    16  */

    17 #pragma once

    18 

    19 #include "FilesystemCommandBase.h"

    20 

    21 namespace relpipe {

    22 namespace in {

    23 namespace filesystem {

    24 

    25 namespace fs = std::filesystem;

    26 using namespace relpipe::writer;

    27 

    28 class FilesystemCommand : public FilesystemCommandBase {

    29 private:

    30 	std::map<string_t, std::shared_ptr<AttributeFinder>> attributeFinders = createAttributeFinders();

    31 

    32 public:

    33 

    34 	void process(std::istream& input, std::ostream& output, Configuration& configuration) {

    35 		std::shared_ptr<RelationalWriter> writer(Factory::create(output));

    36 

    37 		string_t relationName = configuration.relation.empty() ? L"filesystem" : configuration.relation;

    38 

    39 		std::vector<AttributeMetadata> attributesMetadata;

    40 		for (RequestedField field : configuration.fields) {

    41 			std::shared_ptr<AttributeFinder> finder = attributeFinders[field.group];

    42 			if (finder) for (AttributeMetadata m : finder->toMetadata(writer.get(), relationName, field)) attributesMetadata.push_back(m);

    43 			else throw RelpipeWriterException(L"Unsupported field group: " + field.group);

    44 		}

    45 

    46 		writer->startRelation(relationName, attributesMetadata, true);

    47 

    48 

    49 		for (std::stringstream originalName; readNext(input, originalName); reset(originalName)) {

    50 			fs::path file(originalName.str().empty() ? "." : originalName.str()); // interpret empty string as current directory (e.g. result of: find -printf '%P\0')

    51 			bool exists = false;

    52 

    53 			try {

    54 				exists = fs::exists(file);

    55 			} catch (const fs::filesystem_error& e) {

    56 				// we probably do not have permissions to given directory → pretend that the file does not exist

    57 			}

    58 

    59 			for (auto& finder : attributeFinders) finder.second->startFile(file, originalName.str(), exists);

    60 

    61 			for (RequestedField field : configuration.fields) {

    62 				std::shared_ptr<AttributeFinder> finder = attributeFinders[field.group]; // should not be nullptr, because already checked while writing the relation metadata

    63 				finder->writeField(writer.get(), relationName, field);

    64 			}

    65 

    66 			for (auto& finder : attributeFinders) finder.second->endFile();

    67 		}

    68 	}

    69 };

    70 

    71 }

    72 }

    73 }