feat: Add C binding for setting the base path (#1237)

* feat: Add set_resource_dir and binding, add_resource only writes to memory

* test: Add test for reading from ingredient folder using resource_dir

* refactor: Rename back to base path and remove breaking changes

* docs: Update documentation and warning

* chore: Fix test name

* fix: Make test consistent with others

Author: alextrnnn

c2pa_c_ffi/src/c_api.rs

@@ -797,6 +797,31 @@ pub unsafe extern "C" fn c2pa_builder_set_remote_url(
     0 as c_int
 }
 
+/// ⚠️ **Deprecated Soon**
+/// This method is planned to be deprecated in a future release.
+/// Usage should be limited and temporary.
+///
+/// Sets the resource directory on the Builder.
+/// When set, resources that are not found in memory will be searched for in the given directory.
+/// # Parameters
+/// * builder_ptr: pointer to a Builder.
+/// * base_path: pointer to a C string with the resource directory.
+/// # Errors
+/// Returns -1 if there were errors, otherwise returns 0.
+/// The error string can be retrieved by calling c2pa_error.
+/// # Safety
+/// Reads from NULL-terminated C strings.
+#[no_mangle]
+pub unsafe extern "C" fn c2pa_builder_set_base_path(
+    builder_ptr: *mut C2paBuilder,
+    base_path: *const c_char,
+) -> c_int {
+    let mut builder = guard_boxed_int!(builder_ptr);
+    let base_path = from_cstr_or_return_int!(base_path);
+    builder.set_base_path(&base_path);
+    0 as c_int
+}
+
 /// Adds a resource to the C2paBuilder.
 ///
 /// The resource uri should match an identifier in the manifest definition.

sdk/src/builder.rs

@@ -293,6 +293,22 @@ impl Builder {
         self
     }
 
+    /// ⚠️ **Deprecated Soon**
+    /// This method is planned to be deprecated in a future release.
+    /// Usage should be limited and temporary.
+    ///
+    /// Sets the resource directory for this [`Builder`]
+    ///
+    /// # Arguments
+    /// * `base_path` - The directory to search in to find the resources.
+    /// # Returns
+    /// * A mutable reference to the [`Builder`].
+    #[cfg(feature = "file_io")]
+    pub fn set_base_path<P: Into<PathBuf>>(&mut self, base_path: P) -> &mut Self {
+        self.base_path = Some(base_path.into());
+        self
+    }
+
     /// Sets the remote_url for this [`Builder`].
     /// The URL must return the manifest data and is injected into the destination asset when signing.
     /// For remote-only manifests, set the `no_embed` flag to `true`.
@@ -1214,6 +1230,8 @@ mod tests {
     use wasm_bindgen_test::*;
 
     use super::*;
+    #[cfg(feature = "file_io")]
+    use crate::utils::test::fixture_path;
     use crate::{
         assertions::{c2pa_action, BoxHash},
         asset_handlers::jpeg_io::JpegIO,
@@ -2230,4 +2248,32 @@ mod tests {
         assert!(reader_json.contains("Test Ingredient"));
         assert!(reader_json.contains("thumbnail.ingredient"));
     }
+
+    #[cfg(feature = "file_io")]
+    #[test]
+    fn test_base_path() {
+        let mut builder = Builder::new();
+        let ingredient_folder = fixture_path("ingredient");
+        builder.set_base_path(&ingredient_folder);
+        assert_eq!(builder.base_path.as_ref(), Some(&ingredient_folder));
+        let ingredient_json =
+            std::fs::read_to_string(ingredient_folder.join("ingredient.json")).unwrap();
+
+        let ingredient = Ingredient::from_json(&ingredient_json).unwrap();
+        builder.add_ingredient(ingredient);
+
+        let signer = test_signer(SigningAlg::Ps256);
+
+        let mut source = Cursor::new(TEST_IMAGE_CLEAN);
+        let mut dest = Cursor::new(Vec::new());
+
+        builder
+            .sign(&signer, "image/jpeg", &mut source, &mut dest)
+            .unwrap();
+
+        let reader = Reader::from_stream("jpeg", &mut dest).unwrap();
+        let active_manifest = reader.active_manifest().unwrap();
+        let ingredient = active_manifest.ingredients().first().unwrap();
+        assert_eq!(ingredient.title(), Some("C.jpg"));
+    }
 }

sdk/tests/fixtures/ingredient/contentauth_urn_uuid_b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/c2pa.thumbnail.claim.jpeg

@@ -0,0 +1,59 @@
+{
+  "title": "C.jpg",
+  "format": "image/jpeg",
+  "instance_id": "xmp:iid:547f138e-d98d-45b5-a13c-8fd092b4ebc6",
+  "thumbnail": {
+    "format": "image/jpeg",
+    "identifier": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/c2pa.thumbnail.claim.jpeg",
+    "hash": "Nrhmnt6qXlHbrpaDmEMb98m3TyN3PJwniriapw7QM4k="
+  },
+  "relationship": "componentOf",
+  "active_manifest": "contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3",
+  "validation_results": {
+    "activeManifest": {
+      "success": [
+        {
+          "code": "claimSignature.insideValidity",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.signature",
+          "explanation": "claim signature valid"
+        },
+        {
+          "code": "claimSignature.validated",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.signature",
+          "explanation": "claim signature valid"
+        },
+        {
+          "code": "assertion.hashedURI.match",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/c2pa.thumbnail.claim.jpeg",
+          "explanation": "hashed uri matched: self#jumbf=c2pa.assertions/c2pa.thumbnail.claim.jpeg"
+        },
+        {
+          "code": "assertion.hashedURI.match",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/stds.schema-org.CreativeWork",
+          "explanation": "hashed uri matched: self#jumbf=c2pa.assertions/stds.schema-org.CreativeWork"
+        },
+        {
+          "code": "assertion.hashedURI.match",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/c2pa.actions",
+          "explanation": "hashed uri matched: self#jumbf=c2pa.assertions/c2pa.actions"
+        },
+        {
+          "code": "assertion.hashedURI.match",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/c2pa.hash.data",
+          "explanation": "hashed uri matched: self#jumbf=c2pa.assertions/c2pa.hash.data"
+        },
+        {
+          "code": "assertion.dataHash.match",
+          "url": "self#jumbf=/c2pa/contentauth:urn:uuid:b2b1f7fa-b119-4de1-9c0d-c97fbea3f2c3/c2pa.assertions/c2pa.hash.data",
+          "explanation": "data hash valid"
+        }
+      ],
+      "informational": [],
+      "failure": []
+    }
+  },
+  "manifest_data": {
+    "format": "application/c2pa",
+    "identifier": "manifest_data.c2pa"
+  }
+}