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-rw-r--r--log_db/src/log_reader_forward.rs53
1 files changed, 9 insertions, 44 deletions
diff --git a/log_db/src/log_reader_forward.rs b/log_db/src/log_reader_forward.rs
index bfd329b..343d7ff 100644
--- a/log_db/src/log_reader_forward.rs
+++ b/log_db/src/log_reader_forward.rs
@@ -21,29 +21,7 @@ impl<'a> ForwardLogReader {
ret
}
- pub fn new_with_index(
- metadata_file: fs::File,
- data_file: fs::File,
- index: u64,
- ) -> ForwardLogReader {
- let mut ret = ForwardLogReader {
- metadata_reader: io::BufReader::new(metadata_file),
- data_reader: io::BufReader::new(data_file),
- };
-
- ret.metadata_reader
- .seek(io::SeekFrom::Start(
- METADATA_FILE_HEADER_SIZE as u64 + 16 * index,
- ))
- .expect("Seek failed");
-
- ret
- }
-
- fn read_record(&mut self) -> Result<Option<ForwardLogReaderItem>, io::Error> {
- let metadata_index =
- (self.metadata_reader.stream_position()? - METADATA_FILE_HEADER_SIZE as u64) / 16;
-
+ fn read_record(&mut self) -> Result<Option<Record>, io::Error> {
let mut metadata_entry_buf = vec![0; 16]; // 2x u64
if let Err(e) = self.metadata_reader.read_exact(&mut metadata_entry_buf) {
if e.kind() == io::ErrorKind::UnexpectedEof {
@@ -54,37 +32,24 @@ impl<'a> ForwardLogReader {
}
// First u64 is the offset of the record in the data file, second is the length of the record
- let data_offset = u64::from_be_bytes(metadata_entry_buf[0..8].try_into().unwrap());
- let data_length = u64::from_be_bytes(metadata_entry_buf[8..16].try_into().unwrap());
+ let entry_offset = u64::from_be_bytes(metadata_entry_buf[0..8].try_into().unwrap());
+ let entry_length = u64::from_be_bytes(metadata_entry_buf[8..16].try_into().unwrap());
// Use .seek_relative instead of .seek to avoid dropping the BufReader internal buffer when
// the seek distance is small
- let seek_distance = data_offset - self.data_reader.stream_position()?;
+ let seek_distance = entry_offset - self.data_reader.stream_position()?;
self.data_reader.seek_relative(seek_distance as i64)?;
- let mut result_buf = vec![0; data_length as usize];
+ let mut result_buf = vec![0; entry_length as usize];
self.data_reader.read_exact(&mut result_buf)?;
let record = Record::deserialize(&result_buf);
- let item = ForwardLogReaderItem {
- metadata_index,
- data_offset,
- data_length,
- record,
- };
- Ok(Some(item))
+ Ok(Some(record))
}
}
-pub struct ForwardLogReaderItem {
- pub metadata_index: u64,
- pub data_offset: u64,
- pub data_length: u64,
- pub record: Record,
-}
-
impl Iterator for ForwardLogReader {
- type Item = ForwardLogReaderItem;
+ type Item = Record;
fn next(&mut self) -> Option<Self::Item> {
match self.read_record() {
@@ -118,10 +83,10 @@ mod tests {
// There are two records in the log with "schema" with one field: Bytes
- let first_item = forward_log_reader
+ let first_record = forward_log_reader
.next()
.expect("Failed to read the first record");
- assert!(match first_item.record.values() {
+ assert!(match first_record.values() {
[Value::Bytes(bytes)] => bytes.len() == 256,
_ => false,
});