feat(profiling-ffi): ProfileDictionary + ddog_prof_Profile_add2

examples/ffi/build-examples.sh

@@ -34,6 +34,6 @@ echo "Configuring example build..."
 cmake -S examples/ffi -B examples/ffi/build -D Datadog_ROOT=./release
 
 echo "Building examples..."
-cmake --build ./examples/ffi/build
+cmake --build ./examples/ffi/build --target profiles
 
 echo "Done! Example executables are available in examples/ffi/build/"

examples/ffi/profiles.c

@@ -6,6 +6,9 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+// Number of samples to add with each API
+#define NUM_SAMPLES 5000000
+
 int main(void) {
   const ddog_prof_ValueType wall_time = {
       .type_ = DDOG_CHARSLICE_C("wall-time"),
@@ -14,16 +17,27 @@ int main(void) {
   const ddog_prof_Slice_ValueType sample_types = {&wall_time, 1};
   const ddog_prof_Period period = {wall_time, 60};
 
-  ddog_prof_Profile_NewResult new_result = ddog_prof_Profile_new(sample_types, &period);
-  if (new_result.tag != DDOG_PROF_PROFILE_NEW_RESULT_OK) {
-    ddog_CharSlice message = ddog_Error_message(&new_result.err);
-    fprintf(stderr, "%.*s", (int)message.len, message.ptr);
-    ddog_Error_drop(&new_result.err);
+  // Create a ProfilesDictionary for the new API
+  ddog_prof_ProfilesDictionaryHandle dict = {0};
+  ddog_prof_Status dict_status = ddog_prof_ProfilesDictionary_new(&dict);
+  if (dict_status.flags != 0) {
+    fprintf(stderr, "Failed to create dictionary: %s\n", dict_status.err);
+    ddog_prof_Status_drop(&dict_status);
     exit(EXIT_FAILURE);
   }
 
-  ddog_prof_Profile *profile = &new_result.ok;
+  // Create profile using the dictionary
+  ddog_prof_Profile profile = {0};
+  ddog_prof_Status profile_status =
+      ddog_prof_Profile_with_dictionary(&profile, &dict, sample_types, &period);
+  if (profile_status.flags != 0) {
+    fprintf(stderr, "Failed to create profile: %s\n", profile_status.err);
+    ddog_prof_Status_drop(&profile_status);
+    ddog_prof_ProfilesDictionary_drop(&dict);
+    exit(EXIT_FAILURE);
+  }
 
+  // Original API sample
   ddog_prof_Location root_location = {
       // yes, a zero-initialized mapping is valid
       .mapping = (ddog_prof_Mapping){0},
@@ -44,28 +58,107 @@ int main(void) {
       .labels = {&label, 1},
   };
 
-  for (int i = 0; i < 10000000; i++) {
+  for (int i = 0; i < NUM_SAMPLES; i++) {
     label.num = i;
 
-    ddog_prof_Profile_Result add_result = ddog_prof_Profile_add(profile, sample, 0);
+    ddog_prof_Profile_Result add_result = ddog_prof_Profile_add(&profile, sample, 0);
     if (add_result.tag != DDOG_PROF_PROFILE_RESULT_OK) {
       ddog_CharSlice message = ddog_Error_message(&add_result.err);
       fprintf(stderr, "%.*s", (int)message.len, message.ptr);
       ddog_Error_drop(&add_result.err);
     }
   }
 
+  // New API sample using the dictionary
+  // Insert strings into the dictionary
+  ddog_prof_StringId2 function_name_id, filename_id, label_key_id;
+
+  dict_status = ddog_prof_ProfilesDictionary_insert_str(
+      &function_name_id, dict, DDOG_CHARSLICE_C("{main}"), DDOG_PROF_UTF8_OPTION_ASSUME);
+  if (dict_status.flags != 0) {
+    fprintf(stderr, "Failed to insert function name: %s\n", dict_status.err);
+    ddog_prof_Status_drop(&dict_status);
+    goto cleanup;
+  }
+
+  dict_status = ddog_prof_ProfilesDictionary_insert_str(&filename_id, dict,
+                                                        DDOG_CHARSLICE_C("/srv/example/index.php"),
+                                                        DDOG_PROF_UTF8_OPTION_ASSUME);
+  if (dict_status.flags != 0) {
+    fprintf(stderr, "Failed to insert filename: %s\n", dict_status.err);
+    ddog_prof_Status_drop(&dict_status);
+    goto cleanup;
+  }
+
+  dict_status = ddog_prof_ProfilesDictionary_insert_str(
+      &label_key_id, dict, DDOG_CHARSLICE_C("unique_counter"), DDOG_PROF_UTF8_OPTION_ASSUME);
+  if (dict_status.flags != 0) {
+    fprintf(stderr, "Failed to insert label key: %s\n", dict_status.err);
+    ddog_prof_Status_drop(&dict_status);
+    goto cleanup;
+  }
+
+  // Create a function using the dictionary IDs
+  ddog_prof_FunctionId2 function_id;
+  ddog_prof_Function2 function2 = {
+      .name = function_name_id,
+      .system_name = DDOG_PROF_STRINGID2_EMPTY,
+      .file_name = filename_id,
+  };
+
+  dict_status = ddog_prof_ProfilesDictionary_insert_function(&function_id, dict, &function2);
+  if (dict_status.flags != 0) {
+    fprintf(stderr, "Failed to insert function: %s\n", dict_status.err);
+    ddog_prof_Status_drop(&dict_status);
+    goto cleanup;
+  }
+
+  // Create a location using the dictionary IDs
+  ddog_prof_Location2 location2 = {
+      .mapping = (ddog_prof_MappingId2){0}, // null mapping is valid
+      .function = function_id,
+      .address = 0,
+      .line = 0,
+  };
+
+  // New API sample using dictionary IDs
+  ddog_prof_Label2 label2 = {
+      .key = label_key_id,
+      .str = DDOG_CHARSLICE_C(""),
+      .num = 0,
+      .num_unit = DDOG_CHARSLICE_C(""),
+  };
+  const ddog_prof_Sample2 sample2 = {
+      .locations = {&location2, 1},
+      .values = {&value, 1},
+      .labels = {&label2, 1},
+  };
+
+  for (int i = 0; i < NUM_SAMPLES; i++) {
+    label2.num = i;
+
+    ddog_prof_Status add2_status = ddog_prof_Profile_add2(&profile, sample2, 0);
+    if (add2_status.flags != 0) {
+      fprintf(stderr, "add2 error: %s\n", add2_status.err);
+      ddog_prof_Status_drop(&add2_status);
+    }
+  }
+
   //   printf("Press any key to reset and drop...");
   //   getchar();
 
-  ddog_prof_Profile_Result reset_result = ddog_prof_Profile_reset(profile);
+cleanup:
+  ; // Can't have a declaration after a label pre-C23, so use an empty statement.
+  ddog_prof_Profile_Result reset_result = ddog_prof_Profile_reset(&profile);
   if (reset_result.tag != DDOG_PROF_PROFILE_RESULT_OK) {
     ddog_CharSlice message = ddog_Error_message(&reset_result.err);
     fprintf(stderr, "%.*s", (int)message.len, message.ptr);
     ddog_Error_drop(&reset_result.err);
   }
-  ddog_prof_Profile_drop(profile);
+  ddog_prof_Profile_drop(&profile);
 
+  // Drop the dictionary
+  ddog_prof_ProfilesDictionary_drop(&dict);
 
   return 0;
-}
+}

libdd-common/src/error.rs

@@ -8,7 +8,7 @@
 ///  2. It must be valid UTF-8.
 ///  3. It must not allocate to achieve the static bounds.
 ///
-/// Using a c-str literal in Rust achieves all these requirements:
+/// Using a c-str literal in Rust generally achieves all these requirements:
 ///
 /// ```
 /// c"this string is compatible with FfiSafeErrorMessage";

libdd-profiling-ffi/Cargo.toml

@@ -38,6 +38,7 @@ datadog-ffe-ffi = ["dep:datadog-ffe-ffi"]
 build_common = { path = "../build-common" }
 
 [dependencies]
+allocator-api2 = { version = "0.2.21", default-features = false, features = ["alloc"]  }
 anyhow = "1.0"
 libdd-data-pipeline-ffi = { path = "../libdd-data-pipeline-ffi", default-features = false, optional = true }
 libdd-crashtracker-ffi = { path = "../libdd-crashtracker-ffi", default-features = false, optional = true}

libdd-profiling-ffi/cbindgen.toml

@@ -106,6 +106,9 @@ renaming_overrides_prefixing = true
 "CancellationToken" = "struct ddog_OpaqueCancellationToken"
 "Handle_TokioCancellationToken" = "ddog_CancellationToken"
 
+"ArcHandle_ProfilesDictionary" = "ddog_prof_ProfilesDictionaryHandle"
+"ProfileStatus" = "ddog_prof_Status"
+
 [export.mangle]
 rename_types = "PascalCase"
 

libdd-profiling-ffi/src/arc_handle.rs

@@ -0,0 +1,78 @@
+// Copyright 2025-Present Datadog, Inc. https://www.datadoghq.com/
+// SPDX-License-Identifier: Apache-2.0
+
+use crate::profile_error::ProfileError;
+use crate::EmptyHandleError;
+use libdd_profiling::profiles::collections::Arc;
+use std::ptr::{null_mut, NonNull};
+
+/// Opaque FFI handle to an `Arc<T>`'s inner `T`.
+///
+/// Safety rules for implementors/callers:
+/// - Do not create multiple owning `Arc<T>`s from the same raw pointer.
+/// - Always restore the original `Arc` with `into_raw` after any `from_raw`.
+/// - Use `as_inner()` to validate non-null before performing raw round-trips.
+///
+/// From Rust, use [`ArcHandle::try_clone`] to make a reference-counted copy.
+/// From the C FFI, the handle should probably be renamed to avoid generics
+/// bloat garbage, and a *_try_clone API should be provided.
+///
+/// Use [`ArcHandle::drop_resource`] to drop the resource and move this handle
+/// into the empty handle state, which is the default state.
+#[repr(transparent)]
+#[derive(Debug)]
+pub struct ArcHandle<T>(*mut T);
+
+impl<T> Default for ArcHandle<T> {
+    fn default() -> Self {
+        Self(null_mut())
+    }
+}
+
+impl<T> ArcHandle<T> {
+    /// Constructs a new handle by allocating an `ArcHandle<T>` and returning
+    /// its inner pointer as a handle.
+    ///
+    /// Returns OutOfMemory on allocation failure.
+    pub fn new(value: T) -> Result<Self, ProfileError> {
+        let arc = Arc::try_new(value)?;
+        let ptr = Arc::into_raw(arc).as_ptr();
+        Ok(Self(ptr))
+    }
+
+    pub fn try_clone_into_arc(&self) -> Result<Arc<T>, ProfileError> {
+        let clone = self.try_clone()?;
+        // SAFETY: try_clone succeeded so it must not be null.
+        let nn = unsafe { NonNull::new_unchecked(clone.0) };
+        // SAFETY: validated that it isn't null, should otherwise be an Arc.
+        Ok(unsafe { Arc::from_raw(nn) })
+    }
+
+    #[inline]
+    pub fn as_inner(&self) -> Result<&T, EmptyHandleError> {
+        unsafe { self.0.as_ref() }.ok_or(EmptyHandleError)
+    }
+
+    /// Tries to clone the resource this handle points to, and returns a new
+    /// handle to it.
+    pub fn try_clone(&self) -> Result<Self, ProfileError> {
+        let nn = NonNull::new(self.0).ok_or(EmptyHandleError)?;
+        // SAFETY: ArcHandle uses a pointer to T as its repr, and as long as
+        // callers have upheld safety requirements elsewhere, including the
+        // FFI, then there will be a valid object with refcount > 0.
+        unsafe { Arc::try_increment_count(nn.as_ptr())? };
+        Ok(Self(self.0))
+    }
+
+    /// Drops the resource that this handle refers to. It will remain alive if
+    /// there are other handles to the resource which were created by
+    /// successful calls to try_clone. This handle will now be empty and
+    /// operations on it will fail.
+    pub fn drop_resource(&mut self) {
+        // pointers aren't default until Rust 1.88.
+        let ptr = core::mem::replace(&mut self.0, null_mut());
+        if let Some(nn) = NonNull::new(ptr) {
+            drop(unsafe { Arc::from_raw(nn) });
+        }
+    }
+}

libdd-profiling-ffi/src/lib.rs

@@ -7,10 +7,17 @@
 #![cfg_attr(not(test), deny(clippy::todo))]
 #![cfg_attr(not(test), deny(clippy::unimplemented))]
 
+mod arc_handle;
 mod exporter;
+mod profile_error;
+mod profile_status;
 mod profiles;
 mod string_storage;
 
+pub use arc_handle::*;
+pub use profile_error::*;
+pub use profile_status::*;
+
 #[cfg(all(feature = "symbolizer", not(target_os = "windows")))]
 pub use symbolizer_ffi::*;