Making ByteBuffer's description more useful (#2864)

### Motivation:

Resolving the following issue:
#2863

### Modifications:

Rewrote `description` and `debugDescription` on `ByteBuffer` to make it
more useful. Also fixed a bug in the in `hexDumpCompact`.

### Result:

A more useful `description` and `debugDescription`.

---------

Co-authored-by: Franz Busch <f.busch@apple.com>

Sources/NIOCore/ByteBuffer-core.swift

@@ -957,37 +957,32 @@ public struct ByteBuffer {
 }
 
 extension ByteBuffer: CustomStringConvertible, CustomDebugStringConvertible {
- /// A `String` describing this `ByteBuffer`. Example:
+ /// A `String` describing this `ByteBuffer` including length and the bytes it contains (partially).
  ///
- ///  ByteBuffer { readerIndex: 0, writerIndex: 4, readableBytes: 4, capacity: 512, storageCapacity: 1024, slice: 256..<768, storage: 0x0000000103001000 (1024 bytes)}
+ /// For a `ByteBuffer` initialised with `hello world` the description would be the following:
  ///
+ /// [68656c6c6f20776f726c64](11 bytes)
+ ///
+ /// Buffers larger that 64 bytes will get truncated when printing out.
  /// The format of the description is not API.
  ///
  /// - returns: A description of this `ByteBuffer`.
  public var description: String {
- """
- ByteBuffer { \
- readerIndex: \(self.readerIndex), \
- writerIndex: \(self.writerIndex), \
- readableBytes: \(self.readableBytes), \
- capacity: \(self.capacity), \
- storageCapacity: \(self.storageCapacity), \
- slice: \(self._slice), \
- storage: \(self._storage.bytes) (\(self._storage.capacity) bytes) \
- }
- """
+ "[\(self.hexDump(format: .compact(maxBytes: 64)))](\(self.readableBytes) bytes)"
  }
 
- /// A `String` describing this `ByteBuffer` with some portion of the readable bytes dumped too. Example:
+ /// A `String` describing this `ByteBuffer` including length and the bytes it contains (partially).
  ///
- /// ByteBuffer { readerIndex: 0, writerIndex: 4, readableBytes: 4, capacity: 512, slice: 256..<768, storage: 0x0000000103001000 (1024 bytes)}
- /// readable bytes (max 1k): [ 00 01 02 03 ]
+ /// For a `ByteBuffer` initialised with `hello world` the description would be the following:
  ///
+ /// [68656c6c6f20776f726c64](11 bytes)
+ ///
+ /// Buffers larger that 64 bytes will get truncated when printing out.
  /// The format of the description is not API.
  ///
- /// - returns: A description of this `ByteBuffer` useful for debugging.
+ /// - returns: A description of this `ByteBuffer`.
  public var debugDescription: String {
- "\(self.description)\nreadable bytes (max 1k): \(self._storage.dumpBytes(slice: self._slice, offset: self.readerIndex, length: min(1024, self.readableBytes)))"
+ "[\(self.hexDump(format: .compact(maxBytes: 64)))](\(self.readableBytes) bytes)"
  }
 }
 

Sources/NIOCore/ByteBuffer-hexdump.swift

@@ -93,7 +93,7 @@ extension ByteBuffer {
  private func _hexDump(maxBytes: Int, separateWithWhitespace: Bool) -> String {
  // If the buffer length fits in the max bytes limit in the hex dump, just dump the whole thing.
  if self.readableBytes <= maxBytes {
- return self.hexDump(format: .plain)
+ return self._hexDump(separateWithWhitespace: separateWithWhitespace)
  }
 
  var buffer = self

Tests/NIOCoreTests/ByteBufferTest.swift

@@ -1910,6 +1910,11 @@ class ByteBufferTest: XCTestCase {
  XCTAssertEqual("48656c6c6f", buf.hexDump(format: .compact))
  }
 
+ func testHexDumpCompactReadableBytesLessThenMaxBytes() {
+ let buf = ByteBuffer(string: "hello world")
+ XCTAssertEqual("68656c6c6f20776f726c64", buf.hexDump(format: .compact(maxBytes: 100)))
+ }
+
  func testHexDumpCompactEmptyBuffer() {
  let buf = ByteBuffer(string: "")
  XCTAssertEqual("", buf.hexDump(format: .compact))
@@ -3603,4 +3608,32 @@ extension ByteBufferTest {
  }
  }
 
+ func testByteBufferDescription() {
+ let buffer = ByteBuffer(string: "hello world")
+
+ XCTAssertEqual(buffer.description, "[68656c6c6f20776f726c64](11 bytes)")
+
+ XCTAssertEqual(buffer.description, buffer.debugDescription)
+ }
+
+ func testByteBufferDescriptionEmpty() {
+ let buffer = ByteBuffer()
+
+ XCTAssertEqual(buffer.description, "[](0 bytes)")
+
+ XCTAssertEqual(buffer.description, buffer.debugDescription)
+ }
+
+ func testByteBufferDescriptionTruncated() {
+ let buffer = ByteBuffer(
+ string: "iloveswiftnioiloveswiftnioiloveswiftnioiloveswiftnioiloveswiftnioiloveswiftnio"
+ )
+
+ XCTAssertEqual(
+ buffer.description,
+ "[696c6f766573776966746e696f696c6f766573776966746e696f696c6f766573...6966746e696f696c6f766573776966746e696f696c6f766573776966746e696f](78 bytes)"
+ )
+
+ XCTAssertEqual(buffer.description, buffer.debugDescription)
+ }
 }

Tests/NIOCoreTests/NIOAnyDebugTest.swift

@@ -24,7 +24,7 @@ class NIOAnyDebugTest: XCTestCase {
  let bb = ByteBuffer(string: "byte buffer string")
  XCTAssertTrue(
  wrappedInNIOAnyBlock(bb).contains(
- "NIOAny { ByteBuffer { readerIndex: 0, writerIndex: 18, readableBytes: 18, capacity: 32, storageCapacity: 32, slice: _ByteBufferSlice { 0..<32 }, storage: "
+ "NIOAny { [627974652062756666657220737472696e67](18 bytes) }"
  )
  )
  XCTAssertTrue(wrappedInNIOAnyBlock(bb).hasSuffix(" }"))