core/compr: allow inflate work with a custom dictionary

[nihav.git] / nihav-core / src / compr / deflate.rs

diff --git a/nihav-core/src/compr/deflate.rs b/nihav-core/src/compr/deflate.rs
index 2509fc229116d5376a8aff2d65e1e7182079507b..b1266619b87d5b05228dfd21d1d61904e195bef8 100644 (file)
--- a/nihav-core/src/compr/deflate.rs
+++ b/nihav-core/src/compr/deflate.rs
@@ -356,6 +356,14 @@ impl Inflate {
         self.full_pos += len;
         Ok(())
     }
+    ///! Sets custom history for decoding an update for already decoded data.
+    pub fn set_dict(&mut self, dict: &[u8]) {
+        let len = dict.len().min(self.buf.len());
+        let start = dict.len() - len;
+        self.buf[..len].copy_from_slice(&dict[start..]);
+        self.bpos = len;
+        self.full_pos = len;
+    }
     ///! Reports whether decoder has finished decoding the input.
     pub fn is_finished(&self) -> bool {
         match self.state {
@@ -1654,7 +1662,7 @@ impl LZParse for OptimalParser {
         }
         dst.reserve(src.len());
 
-        self.trellis.truncate(0);
+        self.trellis.clear();
         self.trellis.reserve(src.len() + 1);
         for _ in 0..=src.len() {
             self.trellis.push(TNode::default());
@@ -1897,7 +1905,7 @@ impl Deflate {
             Mode::Fixed => {
                 wr.write(final_block as u16, 1);
                 wr.write(1, 2);
-                self.tokens.truncate(0);
+                self.tokens.clear();
                 self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens);
                 let mut codes = CodeHuff::new(true);
                 codes.make_codes(&self.tokens);
@@ -1908,7 +1916,7 @@ impl Deflate {
             Mode::Dynamic => {
                 wr.write(final_block as u16, 1);
                 wr.write(2, 2);
-                self.tokens.truncate(0);
+                self.tokens.clear();
                 self.parser.parse(&self.srcbuf[..self.ssize], &mut self.tokens);
                 let mut codes = CodeHuff::new(false);
                 codes.make_codes(&self.tokens);