From 6acd40719f7f7e68ee2a3142edee4d99af82f293 Mon Sep 17 00:00:00 2001
From: Lonami Exo <totufals@hotmail.com>
Date: Mon, 23 Jul 2018 15:22:45 +0200
Subject: [PATCH] Create a CharacterIterator to read files

---
 .../lonamiwebs/overgram/parser/TLReader.java  | 21 +++----
 .../overgram/utils/CharacterIterator.java     | 61 +++++++++++++++++++
 2 files changed, 70 insertions(+), 12 deletions(-)
 create mode 100644 src/main/java/io/github/lonamiwebs/overgram/utils/CharacterIterator.java

diff --git a/src/main/java/io/github/lonamiwebs/overgram/parser/TLReader.java b/src/main/java/io/github/lonamiwebs/overgram/parser/TLReader.java
index 09c9b9f..5dc076d 100644
--- a/src/main/java/io/github/lonamiwebs/overgram/parser/TLReader.java
+++ b/src/main/java/io/github/lonamiwebs/overgram/parser/TLReader.java
@@ -1,5 +1,7 @@
 package io.github.lonamiwebs.overgram.parser;
 
+import io.github.lonamiwebs.overgram.utils.CharacterIterator;
+
 import java.io.File;
 import java.io.FileReader;
 import java.io.IOException;
@@ -8,7 +10,6 @@ import java.util.List;
 
 public class TLReader {
 
-    private static final int BUFFER_SIZE = 4096;
 
     public static List<TLObject> readTlObjects(final File file) {
         final List<String> lines = readFileWithDelimiter(new File("telegram_api.tl"), ';');
@@ -22,18 +23,14 @@ public class TLReader {
 
     private static List<String> readFileWithDelimiter(final File file, final char delimiter) {
         final List<String> result = new ArrayList<>();
-        try (final FileReader reader = new FileReader(file)) {
-            int read;
-            final char[] buffer = new char[BUFFER_SIZE];
+        try (final CharacterIterator iter = new CharacterIterator(new FileReader(file))) {
             final StringBuilder builder = new StringBuilder();
-            while ((read = reader.read(buffer)) > 0) {
-                for (int i = 0; i < read; ++i) {
-                    if (buffer[i] == delimiter) {
-                        result.add(builder.toString());
-                        builder.setLength(0);
-                    } else {
-                        builder.append(buffer[i]);
-                    }
+            for (char c : iter) {
+                if (c == delimiter) {
+                    result.add(builder.toString());
+                    builder.setLength(0);
+                } else {
+                    builder.append(c);
                 }
             }
         } catch (IOException ignored) {
diff --git a/src/main/java/io/github/lonamiwebs/overgram/utils/CharacterIterator.java b/src/main/java/io/github/lonamiwebs/overgram/utils/CharacterIterator.java
new file mode 100644
index 0000000..d1cc81f
--- /dev/null
+++ b/src/main/java/io/github/lonamiwebs/overgram/utils/CharacterIterator.java
@@ -0,0 +1,61 @@
+package io.github.lonamiwebs.overgram.utils;
+
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.util.Iterator;
+
+public class CharacterIterator implements Iterator<Character>, Iterable<Character>, AutoCloseable {
+
+    private static final int BUFFER_SIZE = 4096;
+
+    private final InputStreamReader reader;
+    private final char[] buffer;
+    private int index;
+    private int length;
+
+    public CharacterIterator(final InputStreamReader reader) {
+        this.reader = reader;
+        buffer = new char[BUFFER_SIZE];
+        index = 0;
+        readNext();
+    }
+
+    @Override
+    public Iterator<Character> iterator() {
+        return this;
+    }
+
+    @Override
+    public boolean hasNext() {
+        if (index == BUFFER_SIZE) {
+            readNext();
+            index = 0;
+        }
+        return length != -1;
+    }
+
+    @Override
+    public Character next() {
+        if (index == BUFFER_SIZE) {
+            readNext();
+            index = 0;
+        }
+        return buffer[index++];
+    }
+
+    @Override
+    public void close() {
+        try {
+            reader.close();
+        } catch (Exception ignored) {
+        }
+    }
+
+    private void readNext() {
+        try {
+            length = reader.read(buffer);
+        } catch (IOException ignored) {
+            length = -1;
+        }
+    }
+}