termwiz: add ImageData::hash

Moves the localized hashing logic from term -> termwiz
where it can be re-used.

refs: #986

Cargo.lock

@@ -4336,6 +4336,7 @@ dependencies = [
  "regex",
  "semver 0.11.0",
  "serde",
+ "sha2",
  "signal-hook 0.1.17",
  "terminfo",
  "termios 0.3.3",
@@ -5142,7 +5143,6 @@ dependencies = [
  "pretty_assertions",
  "pretty_env_logger",
  "serde",
- "sha2",
  "terminfo",
  "termwiz",
  "unicode-segmentation",

term/Cargo.toml

@@ -26,7 +26,6 @@ num-traits = "0.2"
 ordered-float = "2.7"
 palette = "0.5"
 serde = {version="1.0", features = ["rc"]}
-sha2 = "0.9"
 terminfo = "0.7"
 unicode-segmentation = "1.7"
 unicode-width = "0.1"

term/src/terminalstate/image.rs

@@ -162,14 +162,7 @@ impl TerminalState {
 
     /// cache recent images and avoid assigning a new id for repeated data!
     pub(crate) fn raw_image_to_image_data(&mut self, data: ImageDataType) -> Arc<ImageData> {
-        use sha2::Digest;
-        let mut hasher = sha2::Sha256::new();
-        match &data {
-            ImageDataType::EncodedFile(data) => hasher.update(data),
-            ImageDataType::Rgba8 { data, .. } => hasher.update(data),
-        };
-        let key = hasher.finalize().into();
-
+        let key = data.compute_hash();
         if let Some(item) = self.image_cache.get(&key) {
             Arc::clone(item)
         } else {

termwiz/Cargo.toml

@@ -28,6 +28,7 @@ ordered-float = "2.7"
 regex = "1"
 semver = "0.11"
 serde = {version="1.0", features = ["rc", "derive"], optional=true}
+sha2 = "0.9"
 terminfo = "0.7"
 thiserror = "1.0"
 unicode-segmentation = "1.7"

termwiz/src/image.rs

@@ -153,8 +153,6 @@ impl ImageCell {
     }
 }
 
-static IMAGE_ID: ::std::sync::atomic::AtomicUsize = ::std::sync::atomic::AtomicUsize::new(0);
-
 #[cfg_attr(feature = "use_serde", derive(Serialize, Deserialize))]
 #[derive(Clone, PartialEq, Eq)]
 pub enum ImageDataType {
@@ -190,10 +188,25 @@ impl std::fmt::Debug for ImageDataType {
     }
 }
 
+impl ImageDataType {
+    pub fn compute_hash(&self) -> [u8; 32] {
+        use sha2::Digest;
+        let mut hasher = sha2::Sha256::new();
+        match self {
+            ImageDataType::EncodedFile(data) => hasher.update(data),
+            ImageDataType::Rgba8 { data, .. } => hasher.update(data),
+        };
+        hasher.finalize().into()
+    }
+}
+
+static IMAGE_ID: ::std::sync::atomic::AtomicUsize = ::std::sync::atomic::AtomicUsize::new(0);
+
 #[cfg_attr(feature = "use_serde", derive(Serialize, Deserialize))]
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub struct ImageData {
     id: usize,
+    hash: [u8; 32],
     data: ImageDataType,
 }
 
@@ -205,7 +218,8 @@ impl ImageData {
 
     pub fn with_data(data: ImageDataType) -> Self {
         let id = IMAGE_ID.fetch_add(1, ::std::sync::atomic::Ordering::Relaxed);
-        Self { id, data }
+        let hash = data.compute_hash();
+        Self { id, hash, data }
     }
 
     pub fn len(&self) -> usize {
@@ -220,8 +234,11 @@ impl ImageData {
         &self.data
     }
 
-    #[inline]
     pub fn id(&self) -> usize {
         self.id
     }
+
+    pub fn hash(&self) -> [u8; 32] {
+        self.hash
+    }
 }