gstreamer: Improve support for dumping memories and add same functionality to byte slices

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer-rs/-/merge_requests/1362>

Cargo.lock

@@ -845,7 +845,6 @@ dependencies = [
  "option-operations",
  "paste",
  "pin-project-lite",
- "pretty-hex",
  "ron",
  "serde",
  "serde_bytes",
@@ -2017,12 +2016,6 @@ dependencies = [
  "windows-sys 0.52.0",
 ]
 
-[[package]]
-name = "pretty-hex"
-version = "0.4.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "23c6b968ed37d62e35b4febaba13bfa231b0b7929d68b8a94e65445a17e2d35f"
-
 [[package]]
 name = "proc-macro-crate"
 version = "2.0.1"

gstreamer/Cargo.toml

@@ -28,7 +28,6 @@ opt-ops = { package = "option-operations", version = "0.5" }
 serde = { version = "1.0", optional = true, features = ["derive"] }
 serde_bytes = { version = "0.11", optional = true }
 paste = "1.0"
-pretty-hex = "0.4"
 thiserror = "1"
 smallvec = { version = "1.0", features = ["write"] }
 itertools = "0.12"

gstreamer/src/lib.rs

@@ -125,6 +125,7 @@ mod memory_wrapped;
 pub use crate::memory::{MappedMemory, Memory, MemoryMap, MemoryRef};
 #[cfg(feature = "serde")]
 mod buffer_serde;
+pub mod slice;
 
 pub mod sample;
 pub use crate::sample::{Sample, SampleRef};
@@ -342,6 +343,7 @@ pub mod prelude {
         param_spec::GstParamSpecBuilderExt,
         pipeline::GstPipelineExtManual,
         plugin_feature::PluginFeatureExtManual,
+        slice::Dump,
         tag_setter::TagSetterExtManual,
         tags::{CustomTag, Tag},
         task_pool::{TaskHandle, TaskPoolExtManual},

gstreamer/src/memory.rs

@@ -4,7 +4,7 @@ use std::{
     fmt,
     marker::PhantomData,
     mem,
-    ops::{Deref, DerefMut},
+    ops::{Bound, Deref, DerefMut, RangeBounds},
     ptr, slice,
 };
 
@@ -284,8 +284,22 @@ impl MemoryRef {
         unsafe { ffi::gst_memory_resize(self.as_mut_ptr(), offset, size) }
     }
 
-    pub fn dump(&self, size: Option<usize>) -> Dump {
-        Dump { memory: self, size }
+    #[doc(alias = "gst_util_dump_mem")]
+    pub fn dump(&self) -> Dump {
+        Dump {
+            memory: self,
+            start: Bound::Unbounded,
+            end: Bound::Unbounded,
+        }
+    }
+
+    #[doc(alias = "gst_util_dump_mem")]
+    pub fn dump_range(&self, range: impl RangeBounds<usize>) -> Dump {
+        Dump {
+            memory: self,
+            start: range.start_bound().cloned(),
+            end: range.end_bound().cloned(),
+        }
     }
 }
 
@@ -478,22 +492,25 @@ unsafe impl<T> Sync for MappedMemory<T> {}
 
 pub struct Dump<'a> {
     memory: &'a MemoryRef,
-    size: Option<usize>,
+    start: Bound<usize>,
+    end: Bound<usize>,
 }
 
 impl<'a> Dump<'a> {
     fn fmt(&self, f: &mut fmt::Formatter, debug: bool) -> fmt::Result {
-        use pretty_hex::*;
-
         let map = self.memory.map_readable().expect("Failed to map memory");
         let data = map.as_slice();
-        let size = self.size.unwrap_or_else(|| self.memory.size());
-        let data = &data[0..size];
+
+        let dump = crate::slice::Dump {
+            data,
+            start: self.start,
+            end: self.end,
+        };
 
         if debug {
-            write!(f, "{:?}", data.hex_dump())
+            <crate::slice::Dump as fmt::Debug>::fmt(&dump, f)
         } else {
-            write!(f, "{}", data.hex_dump())
+            <crate::slice::Dump as fmt::Display>::fmt(&dump, f)
         }
     }
 }
@@ -920,16 +937,56 @@ mod tests {
 
     #[test]
     fn test_dump() {
+        use std::fmt::Write;
+
         crate::init().unwrap();
 
+        let mut s = String::new();
         let mem = crate::Memory::from_slice(vec![1, 2, 3, 4]);
-        println!("{}", mem.dump(Some(mem.size())));
+        write!(&mut s, "{:?}", mem.dump()).unwrap();
+        assert_eq!(
+            s,
+            "0000:  01 02 03 04                                       ...."
+        );
+        s.clear();
+        write!(&mut s, "{}", mem.dump()).unwrap();
+        assert_eq!(s, "01 02 03 04");
+        s.clear();
 
         let mem = crate::Memory::from_slice(vec![1, 2, 3, 4]);
-        println!("{:?}", mem.dump(Some(2)));
+        write!(&mut s, "{:?}", mem.dump_range(..)).unwrap();
+        assert_eq!(
+            s,
+            "0000:  01 02 03 04                                       ...."
+        );
+        s.clear();
+        write!(&mut s, "{:?}", mem.dump_range(..2)).unwrap();
+        assert_eq!(
+            s,
+            "0000:  01 02                                             .."
+        );
+        s.clear();
+        write!(&mut s, "{:?}", mem.dump_range(2..=3)).unwrap();
+        assert_eq!(
+            s,
+            "0002:  03 04                                             .."
+        );
+        s.clear();
+        write!(&mut s, "{:?}", mem.dump_range(..100)).unwrap();
+        assert_eq!(s, "<end out of range>",);
+        s.clear();
+        write!(&mut s, "{:?}", mem.dump_range(90..100)).unwrap();
+        assert_eq!(s, "<start out of range>",);
+        s.clear();
 
-        let mem = crate::Memory::from_slice(vec![0; 64]);
-        dbg!(mem.dump(None));
+        let mem = crate::Memory::from_slice(vec![0; 19]);
+        write!(&mut s, "{:?}", mem.dump()).unwrap();
+        assert_eq!(
+            s,
+            "0000:  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00   ................\n\
+             0010:  00 00 00                                          ..."
+        );
+        s.clear();
     }
 
     #[test]

gstreamer/src/slice.rs

@@ -0,0 +1,147 @@
+// Take a look at the license at the top of the repository in the LICENSE file.
+
+use std::{
+    fmt,
+    ops::{Bound, RangeBounds},
+};
+
+pub trait ByteSliceExt {
+    #[doc(alias = "gst_util_dump_mem")]
+    fn dump(&self) -> Dump;
+    #[doc(alias = "gst_util_dump_mem")]
+    fn dump_range(&self, range: impl RangeBounds<usize>) -> Dump;
+}
+
+impl<'a> ByteSliceExt for &'a [u8] {
+    fn dump(&self) -> Dump {
+        self.dump_range(..)
+    }
+
+    fn dump_range(&self, range: impl RangeBounds<usize>) -> Dump {
+        Dump {
+            data: self,
+            start: range.start_bound().cloned(),
+            end: range.end_bound().cloned(),
+        }
+    }
+}
+
+pub struct Dump<'a> {
+    pub(crate) data: &'a [u8],
+    pub(crate) start: Bound<usize>,
+    pub(crate) end: Bound<usize>,
+}
+
+impl<'a> Dump<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter, debug: bool) -> fmt::Result {
+        use std::fmt::Write;
+
+        let data = self.data;
+        let len = data.len();
+
+        // Kind of re-implementation of slice indexing to allow handling out of range values better
+        // with specific output strings
+        let mut start_idx = match self.start {
+            Bound::Included(idx) if idx >= len => {
+                write!(f, "<start out of range>")?;
+                return Ok(());
+            }
+            Bound::Excluded(idx) if idx.checked_add(1).map_or(true, |idx| idx >= len) => {
+                write!(f, "<start out of range>")?;
+                return Ok(());
+            }
+            Bound::Included(idx) => idx,
+            Bound::Excluded(idx) => idx + 1,
+            Bound::Unbounded => 0,
+        };
+
+        let end_idx = match self.end {
+            Bound::Included(idx) if idx.checked_add(1).map_or(true, |idx| idx > len) => {
+                write!(f, "<end out of range>")?;
+                return Ok(());
+            }
+            Bound::Excluded(idx) if idx > len => {
+                write!(f, "<end out of range>")?;
+                return Ok(());
+            }
+            Bound::Included(idx) => idx + 1,
+            Bound::Excluded(idx) => idx,
+            Bound::Unbounded => len,
+        };
+
+        if start_idx >= end_idx {
+            write!(f, "<empty range>")?;
+            return Ok(());
+        }
+
+        let data = &data[start_idx..end_idx];
+
+        if debug {
+            for line in data.chunks(16) {
+                match end_idx {
+                    0x00_00..=0xff_ff => write!(f, "{:04x}:  ", start_idx)?,
+                    0x01_00_00..=0xff_ff_ff => write!(f, "{:06x}:  ", start_idx)?,
+                    0x01_00_00_00..=0xff_ff_ff_ff => write!(f, "{:08x}:  ", start_idx)?,
+                    _ => write!(f, "{:016x}:  ", start_idx)?,
+                }
+
+                for (i, v) in line.iter().enumerate() {
+                    if i > 0 {
+                        write!(f, " {:02x}", v)?;
+                    } else {
+                        write!(f, "{:02x}", v)?;
+                    }
+                }
+
+                for _ in line.len()..16 {
+                    write!(f, "   ")?;
+                }
+                write!(f, "   ")?;
+
+                for v in line {
+                    if v.is_ascii() && !v.is_ascii_control() {
+                        f.write_char((*v).into())?;
+                    } else {
+                        f.write_char('.')?;
+                    }
+                }
+
+                start_idx = start_idx.saturating_add(16);
+                if start_idx < end_idx {
+                    writeln!(f)?;
+                }
+            }
+
+            Ok(())
+        } else {
+            for line in data.chunks(16) {
+                for (i, v) in line.iter().enumerate() {
+                    if i > 0 {
+                        write!(f, " {:02x}", v)?;
+                    } else {
+                        write!(f, "{:02x}", v)?;
+                    }
+                }
+
+                start_idx = start_idx.saturating_add(16);
+                if start_idx < end_idx {
+                    writeln!(f)?;
+                }
+            }
+
+            Ok(())
+        }
+    }
+}
+
+impl<'a> fmt::Display for Dump<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.fmt(f, false)
+    }
+}
+
+impl<'a> fmt::Debug for Dump<'a> {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        self.fmt(f, true)
+    }
+}