- attachment data

src/misc.rs

@@ -1,4 +1,5 @@
 use crate::error::Error;
+use std::ffi::CStr;
 use std::mem::MaybeUninit;
 
 pub fn lib_czi_error(code: std::ffi::c_int) -> Result<(), Error> {
@@ -14,7 +15,71 @@ pub fn lib_czi_error(code: std::ffi::c_int) -> Result<(), Error> {
     }
 }
 
-#[derive(Clone, Debug)]
+/// container for some types of attachment data
+pub enum AttachmentData {
+    Float(Vec<f64>),
+    Xml(String),
+    Unknown(Vec<u8>),
+}
+
+impl AttachmentData {
+    pub fn attachment_type(&self) -> &str {
+        match self {
+            Self::Float(_) => "float",
+            Self::Xml(_) => "xml",
+            Self::Unknown(_) => "unknown",
+        }
+    }
+
+    pub(crate) fn from_float(raw: &[u8]) -> Result<Self, Error> {
+        if raw.len() < 8 {
+            Err(Error::MalformedData)
+        } else {
+            let number = u32::from_le_bytes(raw[4..8].try_into().unwrap()) as usize;
+            if raw.len() < 8 * number + 8 {
+                Err(Error::MalformedData)
+            } else {
+                let mut data = Vec::with_capacity(number);
+                for i in 0..number {
+                    data.push(f64::from_le_bytes(
+                        raw[8 + 8 * i..16 + 8 * i].try_into().unwrap(),
+                    ));
+                }
+                Ok(Self::Float(data))
+            }
+        }
+    }
+
+    pub(crate) fn from_xml(raw: &[u8]) -> Result<Self, Error> {
+        Ok(Self::Xml(
+            CStr::from_bytes_until_nul(raw)?
+                .to_string_lossy()
+                .to_string(),
+        ))
+    }
+
+    pub fn try_into_float(&self) -> Result<Vec<f64>, Error> {
+        if let AttachmentData::Float(data) = self {
+            Ok(data.clone())
+        } else {
+            Err(Error::InvalidAttachmentType(
+                self.attachment_type().to_string(),
+            ))
+        }
+    }
+
+    pub fn try_into_xml(&self) -> Result<String, Error> {
+        if let AttachmentData::Xml(data) = self {
+            Ok(data.clone())
+        } else {
+            Err(Error::InvalidAttachmentType(
+                self.attachment_type().to_string(),
+            ))
+        }
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq, Hash)]
 pub enum Dimension {
     /// The Z-dimension.
     Z = 1,
@@ -48,6 +113,10 @@ impl Dimension {
         }
         dimensions
     }
+
+    pub fn is_valid(&self, v: u32) -> bool {
+        v & (*self as u32).pow(2) > 0
+    }
 }
 
 impl TryFrom<i32> for Dimension {