From 51a422f161e7e7cc5b1093a12e004165754ec1b9 Mon Sep 17 00:00:00 2001
From: Adrian Kummerlaender
Date: Sat, 7 Oct 2017 15:45:37 +0200
Subject: Introduce IndexFile class

---
 CMakeLists.txt    |  1 +
 example.cc        | 17 +++++++----------
 src/index.cc      | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 src/index.h       | 29 +++++++++++++++++++++++++++++
 src/util/query.cc |  1 +
 5 files changed, 88 insertions(+), 10 deletions(-)
 create mode 100644 src/index.cc
 create mode 100644 src/index.h

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 45d4b67..6c96f1d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -13,6 +13,7 @@ include_directories(
 add_library(
 	DictzipQuery
 	SHARED
+		src/index.cc
 		src/util/base64.cc
 		src/util/query.cc
 		src/istream/stream.cc
diff --git a/example.cc b/example.cc
index e42a7fb..3727434 100644
--- a/example.cc
+++ b/example.cc
@@ -1,6 +1,5 @@
+#include "index.h"
 #include "istream/stream.h"
-#include "util/base64.h"
-#include "util/query.h"
 
 #include <string>
 #include <iostream>
@@ -12,7 +11,7 @@ std::string get(const std::string& path, std::size_t offset, std::size_t length)
 	result.resize(length);
 
 	stream.seekg(offset);
-	stream.read(result.data(), length);
+	stream.read(&result[0], length);
 
 	return result;
 }
@@ -21,14 +20,12 @@ int main(int argc, char** argv) {
 	if ( argc != 2 ) {
 		std::cerr << "Empty query." << std::endl;
 	} else {
-		// Get index entries of requested word definitions
-		for ( auto& line : dictzip::get_lines_starting_with("gcide.index", argv[1]) ) {
-			// Decode location in compressed archive
-			const std::size_t offset = dictzip::base64_decode(dictzip::get_encoded_offset(line));
-			const std::size_t length = dictzip::base64_decode(dictzip::get_encoded_length(line));
+		dictzip::IndexFile index("gcide.index");
 
-			// Print the GCIDE definition of _Accession_
-			std::cout << get("gcide.dict.dz", offset, length) << std::endl;
+		// Get index entries of requested word definitions
+		for ( auto& entry : index.get(argv[1]) ) {
+			// Print the GCIDE definition
+			std::cout << get("gcide.dict.dz", entry.offset, entry.length) << std::endl;
 		}
 	}
 }
diff --git a/src/index.cc b/src/index.cc
new file mode 100644
index 0000000..c8dc6de
--- /dev/null
+++ b/src/index.cc
@@ -0,0 +1,50 @@
+#include "index.h"
+
+#include "util/query.h"
+#include "util/base64.h"
+
+#include <algorithm>
+
+
+namespace dictzip {
+
+IndexFile::Entry parse_from_line(const std::string& line) {
+	const std::size_t start = line.find_first_of('\t');
+	const std::size_t end   = line.find_last_of('\t');
+
+	return IndexFile::Entry(
+		line.substr(0, start),
+		base64_decode(line.substr(start + 1, end - (start + 1))),
+		base64_decode(line.substr(end + 1)));
+}
+
+IndexFile::Entry::Entry(const std::string& line):
+	IndexFile::Entry{parse_from_line(line)} { }
+
+IndexFile::Entry::Entry(
+	const std::string& word, std::size_t offset, std::size_t length):
+	word(word),
+	offset(offset),
+	length(length) { }
+
+IndexFile::IndexFile(const std::string& path):
+	path_(path) { }
+
+std::vector<IndexFile::Entry> IndexFile::get(const std::string& word) {
+	const std::vector<std::string> lines = get_lines_starting_with(this->path_, word);
+
+	std::vector<Entry> entries;
+	entries.reserve(lines.size());
+
+	std::for_each(
+		lines.begin(),
+		lines.end(),
+		[&entries](const std::string& line) {
+			entries.emplace_back(line);
+		}
+	);
+
+	return entries;
+}
+
+}
diff --git a/src/index.h b/src/index.h
new file mode 100644
index 0000000..50acb2e
--- /dev/null
+++ b/src/index.h
@@ -0,0 +1,29 @@
+#pragma once
+
+#include <string>
+#include <vector>
+#include <cstdint>
+
+namespace dictzip {
+
+class IndexFile {
+public:
+	struct Entry {
+		Entry(const std::string& line);
+		Entry(const std::string& word, std::size_t offset, std::size_t length);
+
+		const std::string word;
+		const std::size_t offset;
+		const std::size_t length;
+	};
+
+	IndexFile(const std::string& path);
+
+	std::vector<Entry> get(const std::string& word);
+
+private:
+	const std::string path_;
+
+};
+
+}
diff --git a/src/util/query.cc b/src/util/query.cc
index f210613..f71b257 100644
--- a/src/util/query.cc
+++ b/src/util/query.cc
@@ -15,6 +15,7 @@ std::vector<std::string> get_lines_starting_with(
 		return std::vector<std::string>{};
 	}
 
+
 	posix_fadvise(fileno(file), 0, 0, 1);  // FDADVICE_SEQUENTIAL
 
 	std::vector<std::string> result;
-- 
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