Buffered input reader and larger batch size

src/main/java/org/genesys/geotools/CountryCLI.java

@@ -20,6 +20,7 @@ import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStreamReader;
 import java.io.OutputStreamWriter;
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.concurrent.Callable;
 import java.util.concurrent.ExecutionException;
@@ -85,13 +86,14 @@ public class CountryCLI {
 		int columnOrigCty = 5;
 
 		CSVWriter writer = new CSVWriter(new OutputStreamWriter(System.out), ',', '"', '\\', "\n");
-		CSVReader reader = new CSVReader(new InputStreamReader(System.in), ',', '"', '\\', 0, false);
+		CSVReader reader = new CSVReader(new BufferedReader(new InputStreamReader(System.in), 10000), ',', '"', '\\',
+				0, false);
 
 		CountryOfOriginServiceImpl countryOfOriginService = new CountryOfOriginServiceImpl();
 		countryOfOriginService.afterPropertiesSet();
 
 		// Thread pool with nThreads concurrent threads
-		int nThreads = 4;
+		int nThreads = 7;
 		ExecutorService threadPool = Executors.newFixedThreadPool(nThreads);
 
 		StopWatch stopWatch = new StopWatch();
@@ -102,19 +104,25 @@ public class CountryCLI {
 		long lastLogTime = 0;
 		stopWatch.start();
 
-		String[][] inputLines = new String[nThreads][];
+		ArrayList<?>[] inputLines = new ArrayList[nThreads];
+		for (int i = 0; i < nThreads; i++) {
+			inputLines[i] = new ArrayList<String[]>();
+		}
 		Future<?>[] futures = new Future<?>[nThreads];
 
 		do {
+			submitted = 0;
+
 			// Reset
-			for (int i = nThreads - 1; i >= 0; i--) {
-				inputLines[i] = null;
+			for (int i = 0; i < nThreads; i++) {
+				inputLines[i].clear();
 				futures[i] = null;
-				submitted = 0;
 			}
 
 			// Submit
-			for (int i = nThreads - 1; i >= 0; i--) {
+			for (int i = 0; i < nThreads; i++) {
+				final ArrayList<String[]> inputs = (ArrayList<String[]>) inputLines[i];
+				for (int j = 0; j < 100; j++) {
 					String[] nextLine = reader.readNext();
 					lineCount++;
 
@@ -122,57 +130,83 @@ public class CountryCLI {
 					long processingTimeSeconds = stopWatch.getSplitTime() / 1000;
 					if ((lineCount % 1000 == 0)
 							|| (lastLogTime != processingTimeSeconds && processingTimeSeconds % 10 == 0)) {
-					System.err.println("FYI, " + lineCount + " entries have been processed in " + processingTimeSeconds
-							+ " = " + (lineCount / processingTimeSeconds) + " lines/second");
+						System.err
+								.println("FYI, " + lineCount + " entries have been processed in "
+										+ processingTimeSeconds + " = " + (lineCount / processingTimeSeconds)
+										+ " lines/second");
 						countryOfOriginService.printCache();
 						lastLogTime = processingTimeSeconds;
 					}
 
-				if (nextLine == null)
+					if (nextLine == null) {
+						System.err.println("No input");
 						break;
+					}
 
-				inputLines[i] = nextLine;
-				submitted++;
+					inputs.add(nextLine);
+				}
 
-				futures[i] = threadPool.submit(new Callable<String>() {
+				if (inputs.size() == 0)
+					break;
+
+				// final int cpuId = i;
+				// System.err.println("Submitted " + cpuId);
+
+				submitted++;
+				futures[i] = threadPool.submit(new Callable<String[]>() {
 					@Override
-					public String call() throws Exception {
+					public String[] call() throws Exception {
+						String[] res = new String[inputs.size()];
+						for (int i = 0; i < inputs.size(); i++) {
+							String[] nextLine = inputs.get(i);
 							try {
 								String origCty = nextLine[columnOrigCty].trim();
 								float longitude = Float.parseFloat(nextLine[columnLongitude].trim());
 								float latitude = Float.parseFloat(nextLine[columnLatitude].trim());
 
 								try {
-								return countryOfOriginService.getCountries(longitude, latitude, origCty,
+									res[i] = countryOfOriginService.getCountries(longitude, latitude, origCty,
 											ALLOWED_DISTANCE_MARGIN);
 
 								} catch (Exception e) {
-								return e.getMessage();
+									res[i] = e.getMessage();
 								}
 							} catch (Throwable e) {
-							return "ERROR: " + e.getMessage();
+								res[i] = "ERROR: " + e.getMessage();
+							}
 						}
+						// System.err.println("Processed " + cpuId);
+						return res;
 					}
 				});
 			}
 
 			// Retrieve results
-			for (int i = nThreads - 1; i >= 0; i--) {
+			for (int i = 0; i < nThreads; i++) {
+				// System.err.println("Getting results " + i);
 				if (futures[i] == null)
 					break;
-				String result = null;
+				final ArrayList<String[]> inputs = (ArrayList<String[]>) inputLines[i];
+
+				String[] result = null;
 				try {
-					result = (String) futures[i].get();
+					result = (String[]) futures[i].get();
 				} catch (InterruptedException | ExecutionException e) {
 					e.printStackTrace();
-					result = e.getMessage();
 				}
-				String[] writeLine = Arrays.copyOf(inputLines[i], inputLines[i].length + 1);
-				writeLine[writeLine.length - 1] = result;
+				// System.err.println("Results " + i);
+				for (int j = 0; j < inputs.size(); j++) {
+					String[] nextLine = inputs.get(j);
+					String[] writeLine = Arrays.copyOf(nextLine, nextLine.length + 1);
+					writeLine[writeLine.length - 1] = result[j];
 					writer.writeNext(writeLine);
 				}
+			}
+
+			// System.err.println("Submitted " + submitted);
 		} while (submitted > 0);
 
+		threadPool.shutdown();
 		stopWatch.stop();
 
 		writer.close();