source code

libs/hbb_common/src/compress.rs

@@ -0,0 +1,50 @@
+use std::cell::RefCell;
+use zstd::block::{Compressor, Decompressor};
+
+thread_local! {
+    static COMPRESSOR: RefCell<Compressor> = RefCell::new(Compressor::new());
+    static DECOMPRESSOR: RefCell<Decompressor> = RefCell::new(Decompressor::new());
+}
+
+/// The library supports regular compression levels from 1 up to ZSTD_maxCLevel(),
+/// which is currently 22. Levels >= 20
+/// Default level is ZSTD_CLEVEL_DEFAULT==3.
+/// value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT
+pub fn compress(data: &[u8], level: i32) -> Vec<u8> {
+    let mut out = Vec::new();
+    COMPRESSOR.with(|c| {
+        if let Ok(mut c) = c.try_borrow_mut() {
+            match c.compress(data, level) {
+                Ok(res) => out = res,
+                Err(err) => {
+                    crate::log::debug!("Failed to compress: {}", err);
+                }
+            }
+        }
+    });
+    out
+}
+
+pub fn decompress(data: &[u8]) -> Vec<u8> {
+    let mut out = Vec::new();
+    DECOMPRESSOR.with(|d| {
+        if let Ok(mut d) = d.try_borrow_mut() {
+            const MAX: usize = 1024 * 1024 * 64;
+            const MIN: usize = 1024 * 1024;
+            let mut n = 30 * data.len();
+            if n > MAX {
+                n = MAX;
+            }
+            if n < MIN {
+                n = MIN;
+            }
+            match d.decompress(data, n) {
+                Ok(res) => out = res,
+                Err(err) => {
+                    crate::log::debug!("Failed to decompress: {}", err);
+                }
+            }
+        }
+    });
+    out
+}