use custom csv writer for performance

performanceDb/src/main/java/org/lucares/performance/db/PdbFile.java

@@ -9,10 +9,13 @@ class PdbFile {
 
 	private final File file;
 
+	private final long offsetInEpochMilli;
+
 	public PdbFile(final Day day, final File file, final Tags tags) {
 		this.day = day;
 		this.file = file;
 		this.tags = tags;
+		offsetInEpochMilli = day.getOffsetInEpochMilli();
 	}
 
 	public static PdbFile today(final File file, final Tags tags) {
@@ -38,7 +41,7 @@ class PdbFile {
 	}
 
 	public long getOffsetInEpochMilli() {
-		return getTimeRange().getFrom().toInstant().toEpochMilli();
+		return offsetInEpochMilli;
 	}
 
 	@Override

performanceDb/src/main/java/org/lucares/performance/db/PdbFileIterator.java

@@ -34,9 +34,9 @@ public class PdbFileIterator implements Iterator<Entry>, AutoCloseable {
 			if (reader == null) {
 				return null;
 			}
-			final Optional<Entry> optionalEntry = reader.readEntry(currentPdbFile.getTags());
+			final Entry entry = reader.readNullableEntry(currentPdbFile.getTags());
 
-			return optionalEntry.orElseGet(() -> {
+			if (entry == null) {
 				nextFile();
 				if (reader == null) {
 					return null;
@@ -44,7 +44,9 @@ public class PdbFileIterator implements Iterator<Entry>, AutoCloseable {
 					final Tags tags = currentPdbFile.getTags();
 					return reader.readEntry(tags).orElse(null);
 				}
-			});
+			}
+
+			return entry;
 
 		}
 

performanceDb/src/main/java/org/lucares/performance/db/PdbReader.java

@@ -30,8 +30,6 @@ class PdbReader implements AutoCloseable {
 	 * @return the value or -1 if end of stream has been reached
 	 */
 	public long readValue() {
-		assertPositionIsAValuePosition();
-
 		return read();
 	}
 
@@ -42,13 +40,11 @@ class PdbReader implements AutoCloseable {
 	 * @throws IOException
 	 */
 	public long readEpochMilli() {
-		assertPositionIsADatePosition();
-
 		final long value = read();
 		if (value < 0) {
 			return -1;
 		}
-		return pdbFile.getDay().getOffsetInEpochMilli() + value;
+		return pdbFile.getOffsetInEpochMilli() + value;
 	}
 
 	public OffsetDateTime readDate() {
@@ -65,11 +61,12 @@ class PdbReader implements AutoCloseable {
 		try {
 			final int read = data.read(buffer);
 
-			if (read < 0) {
-				return -1;
-			}
 			if (read != BYTES_PER_VALUE) {
-				throw new IllegalStateException("invalid file");
+				if (read < 0) {
+					return -1;
+				} else {
+					throw new IllegalStateException("invalid file");
+				}
 			}
 			return BitFiddling.makeLong(buffer[0], buffer[1], buffer[2], buffer[3]);
 		} catch (final IOException e) {
@@ -77,40 +74,6 @@ class PdbReader implements AutoCloseable {
 		}
 	}
 
-	private void assertPositionIsADatePosition() {
-		try {
-			assertPositionIsValid();
-
-			if ((data.getFilePointer() / BYTES_PER_VALUE) % 2 != 0) {
-				throw new IllegalStateException("file pointer is not at a date position: " + data.getFilePointer());
-			}
-		} catch (final IOException e) {
-			throw new ReadRuntimeException(e);
-		}
-	}
-
-	private void assertPositionIsAValuePosition() {
-		assertPositionIsValid();
-		try {
-			if ((data.getFilePointer() / BYTES_PER_VALUE) % 2 != 1) {
-				throw new IllegalStateException("file pointer is not at a value position: " + data.getFilePointer());
-			}
-		} catch (final IOException e) {
-			throw new ReadRuntimeException(e);
-		}
-	}
-
-	private void assertPositionIsValid() {
-		try {
-			if (data.getFilePointer() % BYTES_PER_VALUE != 0) {
-				throw new IllegalStateException("file pointer is at an illegal position. It is at "
-						+ data.getFilePointer() + " which is not divisible by " + BYTES_PER_VALUE);
-			}
-		} catch (final IOException e) {
-			throw new ReadRuntimeException(e);
-		}
-	}
-
 	/**
 	 * Seek to the n-th value.
 	 *
@@ -183,17 +146,22 @@ class PdbReader implements AutoCloseable {
 		}
 	}
 
-	public Optional<Entry> readEntry(final Tags tags) throws ReadRuntimeException {
+	Entry readNullableEntry(final Tags tags) throws ReadRuntimeException {
 		final long epochMilli = readEpochMilli();
 		if (epochMilli < 0) {
-			return Optional.empty();
+			return null;
 		}
 		final long value = readValue();
 
 		if (value < 0) {
-			return Optional.empty();
+			return null;
 		}
-		return Optional.of(new Entry(epochMilli, value, tags));
+		return new Entry(epochMilli, value, tags);
+	}
+
+	public Optional<Entry> readEntry(final Tags tags) throws ReadRuntimeException {
+
+		return Optional.ofNullable(readNullableEntry(tags));
 	}
 
 }