From 379a2c82e5f87e5eb0cfdb92db475d0fd854f574 Mon Sep 17 00:00:00 2001
From: Christian Eltzschig <me@elchris.org>
Date: Mon, 25 Dec 2023 03:06:55 +0100
Subject: [PATCH] [#56] Introduce `from_bytes_truncated`

---
 ROADMAP.md                                    | 11 ++++++
 doc/release-notes/iceoryx2-unreleased.md      |  2 +-
 iceoryx2-bb/container/src/byte_string.rs      | 25 +++++++++++++
 .../container/tests/byte_string_tests.rs      | 37 +++++++++++++++----
 4 files changed, 66 insertions(+), 9 deletions(-)

diff --git a/ROADMAP.md b/ROADMAP.md
index bec0acf75..20d60f879 100644
--- a/ROADMAP.md
+++ b/ROADMAP.md
@@ -7,6 +7,17 @@
 * [ ] `#![no_std]` on `stable` on all tier 1 platforms
 * [ ] completely dynamic setup with dynamic shared memory
 
+## Shared Memory Container & Types
+
+* [ ] Make `iceoryx2_bb_container` public with announcement
+* [ ] Create and document dynamic size container concept for shared memory and apply it
+        to all existing containers: `ByteString`, `Vec`, `Queue`
+    * Open Question: How can these containers be cloned, copied?
+* [ ] Introduce additional containers: `HashMap`, `Tree`, `Set`, `List`
+* [ ] Introduce elementary types, look into: `simple-si-units` crate
+    * Add types like: memory size, percentage, strict percentage (0..100), data throughput, resolution
+        (further types found in informatics)
+
 ## Language Bindings
 
 * [ ] C
diff --git a/doc/release-notes/iceoryx2-unreleased.md b/doc/release-notes/iceoryx2-unreleased.md
index e8a510de1..918d3b8c2 100644
--- a/doc/release-notes/iceoryx2-unreleased.md
+++ b/doc/release-notes/iceoryx2-unreleased.md
@@ -22,7 +22,7 @@
 
 ### New API features
 
- * Example [#1](https://github.com/eclipse-iceoryx/iceoryx2/issues/1)
+ * Add `FixedSizeByteString::from_bytes_truncated` [#56](https://github.com/eclipse-iceoryx/iceoryx2/issues/56)
 
 ### API Breaking Changes
 
diff --git a/iceoryx2-bb/container/src/byte_string.rs b/iceoryx2-bb/container/src/byte_string.rs
index 2f1fb638c..17763bd5d 100644
--- a/iceoryx2-bb/container/src/byte_string.rs
+++ b/iceoryx2-bb/container/src/byte_string.rs
@@ -237,6 +237,31 @@ impl<const CAPACITY: usize> FixedSizeByteString<CAPACITY> {
         Ok(new_self)
     }
 
+    /// Creates a new [`FixedSizeByteString`] from a byte slice. If the byte slice does not fit
+    /// into the [`FixedSizeByteString`] it will be truncated.
+    pub fn from_bytes_truncated(bytes: &[u8]) -> Self {
+        let mut new_self = Self::new();
+        new_self.len = std::cmp::min(bytes.len(), CAPACITY);
+        unsafe {
+            std::ptr::copy(
+                bytes.as_ptr(),
+                new_self.data.as_ptr() as *mut u8,
+                bytes.len(),
+            )
+        };
+
+        let zero = 0u8;
+        unsafe {
+            std::ptr::copy(
+                &zero,
+                new_self.data.as_ptr().add(new_self.len) as *mut u8,
+                1,
+            )
+        };
+
+        new_self
+    }
+
     /// Creates a new byte string from a given null-terminated string
     ///
     /// # Safety
diff --git a/iceoryx2-bb/container/tests/byte_string_tests.rs b/iceoryx2-bb/container/tests/byte_string_tests.rs
index 0e58d6efd..1c1e9b633 100644
--- a/iceoryx2-bb/container/tests/byte_string_tests.rs
+++ b/iceoryx2-bb/container/tests/byte_string_tests.rs
@@ -47,19 +47,40 @@ fn fixed_size_byte_string_from_bytes_works() {
     assert_that!(sut.pop(), eq Some(b'd'));
 }
 
+#[test]
+fn fixed_size_byte_string_from_bytes_truncated_works() {
+    let sut = Sut::from_bytes(b"bonjour world");
+    assert_that!(sut, is_ok);
+    let mut sut = sut.unwrap();
+
+    assert_that!(sut, is_not_empty);
+    assert_that!(sut.is_full(), eq false);
+    assert_that!(sut, len 13);
+    assert_that!(sut, eq b"bonjour world");
+    assert_that!(sut, ne b"bonjour world! woo");
+    assert_that!(sut.as_bytes(), eq b"bonjour world");
+    assert_that!(sut.as_mut_bytes(), eq b"bonjour world");
+    assert_that!(sut.as_bytes_with_nul(), eq b"bonjour world\0");
+    assert_that!(sut.pop(), eq Some(b'd'));
+}
+
 #[test]
 fn fixed_size_byte_string_from_byte_slice_works() {
-    let mut sut = Sut::from(b"hello world!");
+    let sut = FixedSizeByteString::<5>::from_bytes_truncated(b"hell");
 
     assert_that!(sut, is_not_empty);
     assert_that!(sut.is_full(), eq false);
-    assert_that!(sut, len 12);
-    assert_that!(sut, eq b"hello world!");
-    assert_that!(sut, ne b"hello world! woo");
-    assert_that!(sut.as_bytes(), eq b"hello world!");
-    assert_that!(sut.as_mut_bytes(), eq b"hello world!");
-    assert_that!(sut.as_bytes_with_nul(), eq b"hello world!\0");
-    assert_that!(sut.pop(), eq Some(b'!'));
+    assert_that!(sut, len 4);
+    assert_that!(sut, eq b"hell");
+    assert_that!(sut.as_bytes_with_nul(), eq b"hell\0");
+
+    let sut = FixedSizeByteString::<5>::from_bytes_truncated(b"hello world");
+
+    assert_that!(sut, is_not_empty);
+    assert_that!(sut.is_full(), eq true);
+    assert_that!(sut, len 5);
+    assert_that!(sut, eq b"hello");
+    assert_that!(sut.as_bytes_with_nul(), eq b"hello\0");
 }
 
 #[test]