FileInputProvider

mkordus · Sep 23, 2017 · 5ad7d91 · 5ad7d91
1 parent cc4f0ee
commit 5ad7d91
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Showing 5 changed files with 115 additions and 3 deletions.
diff --git a/src/main/java/pega/command/executor/SortCommandExecutor.java b/src/main/java/pega/command/executor/SortCommandExecutor.java
@@ -2,11 +2,12 @@
 
 import pega.command.SortCommand;
 
+import java.io.IOException;
 import java.util.Arrays;
 
 public class SortCommandExecutor {
 
-    public void execute(SortCommand command) {
+    public void execute(SortCommand command) throws IOException {
         int[] input = command.getInputProvider().getInput();
 
         Arrays.parallelSort(input);

diff --git a/src/main/java/pega/io/FileInputProvider.java b/src/main/java/pega/io/FileInputProvider.java
@@ -0,0 +1,33 @@
+package pega.io;
+
+import java.io.*;
+
+public class FileInputProvider implements InputProvider {
+
+    private final File file;
+    private final int startPosition;
+    private final int numberOfElementsToRead;
+    private final int intSize = 4;
+
+    public FileInputProvider(File file, Integer startPosition, Integer numberOfElementsToRead) {
+
+        this.file = file;
+        this.startPosition = startPosition;
+        this.numberOfElementsToRead = numberOfElementsToRead;
+    }
+
+    @Override
+    public int[] getInput() throws IOException {
+        int[] buffer = new int[numberOfElementsToRead];
+
+        try (RandomAccessFile input = new RandomAccessFile(file, "r")) {
+            input.seek(startPosition * intSize);
+
+            for (int index = 0; index < numberOfElementsToRead; index++) {
+                buffer[index] = input.readInt();
+            }
+        }
+
+        return buffer;
+    }
+}
diff --git a/src/main/java/pega/io/InputProvider.java b/src/main/java/pega/io/InputProvider.java
@@ -1,5 +1,8 @@
 package pega.io;
 
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
 public interface InputProvider {
-    int[] getInput();
+    int[] getInput() throws IOException;
 }
diff --git a/src/test/java/pega/command/executor/SortCommandExecutorTest.java b/src/test/java/pega/command/executor/SortCommandExecutorTest.java
@@ -10,6 +10,9 @@
 import pega.io.InputProvider;
 import pega.io.OutputProvider;
 
+import java.io.FileNotFoundException;
+import java.io.IOException;
+
 import static org.mockito.BDDMockito.given;
 import static org.mockito.Mockito.*;
 
@@ -30,7 +33,7 @@ public void setUp() {
 
     @Test
     @UseDataProvider("dataProvider")
-    public void executeTest(int[] input, int[] output) {
+    public void executeTest(int[] input, int[] output) throws IOException {
         given(inputProvider.getInput())
             .willReturn(input);
 

diff --git a/src/test/java/pega/io/FileInputProviderTest.java b/src/test/java/pega/io/FileInputProviderTest.java
@@ -0,0 +1,72 @@
+package pega.io;
+
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.TemporaryFolder;
+import org.junit.runner.RunWith;
+import org.mockito.junit.MockitoJUnitRunner;
+
+import java.io.File;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+
+import static org.junit.Assert.*;
+
+@RunWith(MockitoJUnitRunner.class)
+public class FileInputProviderTest {
+
+    @Rule
+    public TemporaryFolder folder = new TemporaryFolder();
+    private File file;
+
+    @Before
+    public void setUp() throws IOException {
+        file = folder.newFile("test");
+
+        try (RandomAccessFile accessFile = new RandomAccessFile(
+            file,
+            "rw"
+        )) {
+            for (int i = 0; i < 10; i++) {
+                accessFile.writeInt(i + 1);
+            }
+        }
+    }
+
+    @Test
+    public void testGetAllData() throws IOException {
+        FileInputProvider provider = new FileInputProvider(
+            file,
+            0,
+            10
+        );
+
+        int[] expectedResult = {1, 2 ,3 ,4 ,5, 6, 7, 8, 9, 10};
+        assertArrayEquals(expectedResult, provider.getInput());
+    }
+
+    @Test
+    public void testGetDataToMiddle() throws IOException {
+        FileInputProvider provider = new FileInputProvider(
+            file,
+            0,
+            5
+        );
+
+        int[] expectedResult = {1, 2 ,3 ,4 ,5};
+        assertArrayEquals(expectedResult, provider.getInput());
+    }
+
+    @Test
+    public void testGetDataFromMiddle() throws IOException {
+        FileInputProvider provider = new FileInputProvider(
+            file,
+            5,
+            5
+        );
+
+        int[] expectedResult = {6, 7, 8, 9, 10};
+        assertArrayEquals(expectedResult, provider.getInput());
+    }
+}