Defining Input Stream providers

Signed-off-by: Ricardo Zanini <[email protected]>

Author: ricardozanini

deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/codegen/OpenApiGeneratorCodeGenBase.java

@@ -1,7 +1,5 @@
 package io.quarkiverse.openapi.generator.deployment.codegen;
 
-import static io.quarkiverse.openapi.generator.deployment.SpecConfig.getResolvedBasePackageProperty;
-
 import java.io.IOException;
 import java.nio.file.Files;
 import java.nio.file.Path;
@@ -13,6 +11,8 @@
 import io.quarkus.deployment.CodeGenContext;
 import io.quarkus.deployment.CodeGenProvider;
 
+import static io.quarkiverse.openapi.generator.deployment.SpecConfig.getResolvedBasePackageProperty;
+
 /**
  * Code generation for OpenApi Client. Generates Java classes from OpenApi spec files located in src/main/openapi or
  * src/test/openapi
@@ -42,15 +42,7 @@ public boolean trigger(CodeGenContext context) throws CodeGenException {
                         .map(Path::toString)
                         .filter(s -> s.endsWith(this.inputExtension()))
                         .map(Path::of).forEach(openApiFilePath -> {
-                            final OpenApiClientGeneratorWrapper generator = new OpenApiClientGeneratorWrapper(
-                                    openApiFilePath.normalize(), outDir)
-                                            .withCircuitBreakerConfiguration(CircuitBreakerConfigurationParser.parse(
-                                                    context.config()));
-
-                            context.config()
-                                    .getOptionalValue(getResolvedBasePackageProperty(openApiFilePath), String.class)
-                                    .ifPresent(generator::withBasePackage);
-                            generator.generate();
+                            this.generate(context, openApiFilePath, outDir);
                         });
             } catch (IOException e) {
                 throw new CodeGenException("Failed to generate java files from OpenApi files in " + openApiDir.toAbsolutePath(),
@@ -60,4 +52,15 @@ public boolean trigger(CodeGenContext context) throws CodeGenException {
         }
         return false;
     }
+
+    protected void generate(CodeGenContext context, final Path openApiFilePath, final Path outDir) {
+        final OpenApiClientGeneratorWrapper generator = new OpenApiClientGeneratorWrapper(
+                openApiFilePath.normalize(), outDir)
+                .withCircuitBreakerConfiguration(CircuitBreakerConfigurationParser.parse(
+                        context.config()));
+        context.config()
+                .getOptionalValue(getResolvedBasePackageProperty(openApiFilePath), String.class)
+                .ifPresent(generator::withBasePackage);
+        generator.generate();
+    }
 }

deployment/src/main/java/io/quarkiverse/openapi/generator/deployment/codegen/OpenApiGeneratorStreamCodeGen.java

@@ -0,0 +1,101 @@
+package io.quarkiverse.openapi.generator.deployment.codegen;
+
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UncheckedIOException;
+import java.nio.channels.Channels;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.file.Path;
+import java.nio.file.Paths;
+import java.util.List;
+import java.util.ServiceLoader;
+import java.util.stream.Collectors;
+import java.util.zip.CRC32;
+import java.util.zip.CheckedInputStream;
+
+import org.eclipse.microprofile.config.Config;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import io.quarkiverse.openapi.generator.OpenApiSpecInputProvider;
+import io.quarkus.bootstrap.prebuild.CodeGenException;
+import io.quarkus.deployment.CodeGenContext;
+
+public class OpenApiGeneratorStreamCodeGen extends OpenApiGeneratorCodeGenBase {
+
+    private static final Logger LOGGER = LoggerFactory.getLogger(OpenApiGeneratorStreamCodeGen.class);
+
+    private List<OpenApiSpecInputProvider> providers;
+
+    public OpenApiGeneratorStreamCodeGen() {
+
+    }
+
+    private void loadServices() {
+        final ServiceLoader<OpenApiSpecInputProvider> loader = ServiceLoader.load(OpenApiSpecInputProvider.class);
+        providers = loader.stream().map(ServiceLoader.Provider::get).collect(Collectors.toList());
+    }
+
+    @Override
+    public String providerId() {
+        return "open-api-stream";
+    }
+
+    // unused by this CodeGenProvider since we rely on the input coming from ServiceLoaders
+    @Override
+    public String inputExtension() {
+        return ".yaml";
+    }
+
+    // unused by this CodeGenProvider since we rely on the input coming from ServiceLoaders
+    @Override
+    public String inputDirectory() {
+        return "openapi";
+    }
+
+    @Override
+    public boolean trigger(CodeGenContext context) throws CodeGenException {
+        final Path outDir = context.outDir();
+        boolean generated = false;
+
+        for (final OpenApiSpecInputProvider provider : this.providers) {
+            for (final InputStream is : provider.read()) {
+                // TODO: in the future, we can use the checksum to not generate the stub files again
+                final String checksum = generateChecksumCRC32(is);
+                final Path openApiFilePath = Paths.get(outDir.toString(), checksum + ".yaml");
+
+                try (ReadableByteChannel channel = Channels.newChannel(is);
+                        FileOutputStream output = new FileOutputStream(openApiFilePath.toString())) {
+                    output.getChannel().transferFrom(channel, 0, Integer.MAX_VALUE);
+                    this.generate(context, openApiFilePath, outDir);
+                    generated = true;
+                } catch (IOException e) {
+                    throw new UncheckedIOException("Fail to save openapi file", e);
+                }
+            }
+        }
+        return generated;
+    }
+
+    private String generateChecksumCRC32(final InputStream is) {
+        CheckedInputStream checkedInputStream = new CheckedInputStream(is, new CRC32());
+        byte[] buffer = new byte[2048];
+        while (true) {
+            try {
+                if (checkedInputStream.read(buffer, 0, buffer.length) < 0) {
+                    break;
+                }
+            } catch (IOException e) {
+                throw new UncheckedIOException("Fail to calculate checksum for InputStream", e);
+            }
+        }
+        return String.valueOf(checkedInputStream.getChecksum().getValue());
+    }
+
+    @Override
+    public boolean shouldRun(Path sourceDir, Config config) {
+        this.loadServices();
+        return !this.providers.isEmpty();
+    }
+}

deployment/src/main/resources/META-INF/services/io.quarkus.deployment.CodeGenProvider

@@ -1,3 +1,4 @@
 io.quarkiverse.openapi.generator.deployment.codegen.OpenApiGeneratorJsonCodeGen
 io.quarkiverse.openapi.generator.deployment.codegen.OpenApiGeneratorYamlCodeGen
 io.quarkiverse.openapi.generator.deployment.codegen.OpenApiGeneratorYmlCodeGen
+io.quarkiverse.openapi.generator.deployment.codegen.OpenApiGeneratorStreamCodeGen

integration-tests/src/main/java/io/quarkiverse/openapi/generator/it/providers/ClassPathOpenApiSpecInputProvider.java

@@ -0,0 +1,17 @@
+package io.quarkiverse.openapi.generator.it.providers;
+
+import java.io.InputStream;
+import java.util.Collections;
+import java.util.List;
+
+import io.quarkiverse.openapi.generator.OpenApiSpecInputProvider;
+
+/**
+ * Class used during tests to read the spec file from an alternative input.
+ */
+public class ClassPathOpenApiSpecInputProvider implements OpenApiSpecInputProvider {
+    @Override
+    public List<InputStream> read() {
+        return Collections.singletonList(this.getClass().getResourceAsStream("petstore.json"));
+    }
+}

integration-tests/src/main/resources/META-INF/services/io.quarkiverse.openapi.generator.OpenApiSpecInputProvider

@@ -0,0 +1 @@
+io.quarkiverse.openapi.generator.it.providers.ClassPathOpenApiSpecInputProvider

integration-tests/src/main/resources/specs/README.md

@@ -0,0 +1,5 @@
+# Providing OpenAPI spec files via InputStream
+
+This directory is just meant to be used in the integration test cases. Instead of reading from the `src/main/openapi` directory, a spec file can also be read via a given `InputStream`. 
+
+For this to work, clients must implement the `OpenApiSpecInputProvider` interface. The implementation read the files from any other source (an HTTP server, for example), and provide the input stream.

integration-tests/src/main/openapi/petstore.json renamed to integration-tests/src/main/resources/specs/petstore.json

@@ -0,0 +1,18 @@
+package io.quarkiverse.openapi.generator;
+
+import java.io.InputStream;
+import java.util.List;
+
+/**
+ * Provider interface for clients to dynamically provide their own OpenAPI specification files.
+ */
+public interface OpenApiSpecInputProvider {
+
+    /**
+     * Fetch OpenAPI specification files from a given source.
+     * 
+     * @return a list of spec files in {@link InputStream} format.
+     */
+    List<InputStream> read();
+
+}