Add function to BDFWriter to set the compression level

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "bdflib"
-version = "0.1.1"
+version = "0.1.2"
 authors = ["trivernis <trivernis@gmail.com>"]
 edition = "2018"
 license-file = "LICENSE"

src/chunks.rs

@@ -144,9 +144,9 @@ impl GenericChunk {
     }
 
     /// Compresses the data of the chunk using lzma with a level of 6
-    pub fn compress(&mut self) -> Result<(), Error> {
+    pub fn compress(&mut self, level: u32) -> Result<(), Error> {
         let data = self.data.as_slice();
-        let mut compressor = XzEncoder::new(data, 1);
+        let mut compressor = XzEncoder::new(data, level);
         let mut compressed: Vec<u8> = Vec::new();
         compressor.read_to_end(&mut compressed)?;
         self.length = compressed.len() as u32;

src/io.rs

@@ -24,6 +24,7 @@ pub struct BDFWriter {
     data_entries: Vec<DataEntry>,
     head_written: bool,
     compressed: bool,
+    compression_level: u32,
 }
 
 impl BDFWriter {
@@ -36,6 +37,7 @@ impl BDFWriter {
             writer,
             head_written: false,
             compressed: compress,
+            compression_level: 1,
         }
     }
 
@@ -81,7 +83,7 @@ impl BDFWriter {
         let mut data_chunk =
             GenericChunk::from_data_entries(&self.data_entries, &self.lookup_table);
         if self.compressed {
-            data_chunk.compress()?;
+            data_chunk.compress(self.compression_level)?;
         }
         let data = data_chunk.serialize();
         self.writer.write(data.as_slice())?;
@@ -95,6 +97,11 @@ impl BDFWriter {
     pub fn flush_writer(&mut self) -> Result<(), Error> {
         self.writer.flush()
     }
+
+    /// Sets the compression level for lzma compression
+    pub fn set_compression_level(&mut self, level: u32) {
+        self.compression_level = level;
+    }
 }
 
 impl BDFReader {

src/lib.rs

@@ -37,6 +37,7 @@ mod tests {
     #[test]
     fn it_writes_compressed() -> Result<(), Error> {
         let mut writer = new_writer("tmp2.bdf", 2, true)?;
+        writer.set_compression_level(3);
 
         writer.add_lookup_entry(HashEntry::new(FOO.to_string(), 4))?;
         writer.add_lookup_entry(HashEntry::new(BAR.to_string(), 5))?;