Add ability to write avscs directly to streams/writers

helper/helper-common/src/main/java/com/linkedin/avroutil1/compatibility/AvroAdapter.java

@@ -12,6 +12,8 @@
 import java.io.ObjectInput;
 import java.io.ObjectOutput;
 import java.io.OutputStream;
+import java.io.StringWriter;
+import java.io.Writer;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashMap;
@@ -196,7 +198,25 @@ default Schema newEnumSchema(String name, String doc, String namespace, List<Str
    * @param schema a schema to print out as (exploded/fully-defined) avsc
    * @return the given schema as avsc
    */
-  String toAvsc(Schema schema, AvscGenerationConfig config);
+  default String toAvsc(Schema schema, AvscGenerationConfig config) {
+    StringWriter writer = new StringWriter();
+    writeAvsc(schema, config, writer);
+    return writer.toString();
+  }
+
+  /**
+   * "serialize" a {@link Schema} to avsc format and write it to the given writer.
+   * @param schema a schema to print out as (exploded/fully-defined) avsc
+   * @param writer the writer to write the serialized schema to.
+   */
+  void writeAvsc(Schema schema, AvscGenerationConfig config, Writer writer);
+
+  /**
+   * "serialize" a {@link Schema} to avsc format and write it to the given output stream.
+   * @param schema a schema to print out as (exploded/fully-defined) avsc
+   * @param stream the output stream to write the serialized schema to.
+   */
+  void writeAvsc(Schema schema, AvscGenerationConfig config, OutputStream stream);
 
   /***
    * Instantiates and returns com.linkedin.avroutil1.compatibility.AvroWriter for the provided configs, plugin list

helper/helper-common/src/main/java/com/linkedin/avroutil1/compatibility/AvscWriter.java

@@ -11,7 +11,9 @@
 import com.linkedin.avroutil1.compatibility.backports.AvroNames;
 import com.linkedin.avroutil1.normalization.AvscWriterPlugin;
 import java.io.IOException;
+import java.io.OutputStream;
 import java.io.StringWriter;
+import java.io.Writer;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Collections;
@@ -137,24 +139,37 @@ protected AvscWriter(boolean pretty, boolean preAvro702, boolean addAliasesForAv
         this._plugins = plugins == null ? Collections.emptyList() : plugins;
     }
 
-    public String toAvsc(Schema schema) {
-        try {
-            AvroNames names = new AvroNames();
-            StringWriter writer = new StringWriter();
-            G gen = createJsonGenerator(writer);
-            if(isLegacy) {
-                toJsonLegacy(schema, names, "", "", gen);
-            } else {
-                toJson(schema, names, "", "", gen);
-            }
+    public void writeAvsc(Schema schema, OutputStream outputStream) {
+        try (G generator = createJsonGenerator(outputStream)) {
+            writeAvsc(schema, generator);
+        } catch (IOException e) {
+            throw new AvroRuntimeException(e);
+        }
+    }
 
-            gen.flush();
-            return writer.toString();
+    public void writeAvsc(Schema schema, Writer writer) {
+        try (G generator = createJsonGenerator(writer)) {
+            writeAvsc(schema, generator);
         } catch (IOException e) {
             throw new AvroRuntimeException(e);
         }
     }
 
+    private void writeAvsc(Schema schema, G generator) throws IOException {
+        AvroNames names = new AvroNames();
+        if (isLegacy) {
+            toJsonLegacy(schema, names, "", "", generator);
+        } else {
+            toJson(schema, names, "", "", generator);
+        }
+    }
+
+    public String toAvsc(Schema schema) {
+        StringWriter writer = new StringWriter();
+        writeAvsc(schema, writer);
+        return writer.toString();
+    }
+
     protected void toJsonLegacy(
         Schema schema,
         AvroNames names,
@@ -728,7 +743,9 @@ protected Avro702Data writeName(
 
     //json generator methods (will vary by jackson version across different avro versions)
 
-    protected abstract G createJsonGenerator(StringWriter writer) throws IOException;
+    protected abstract G createJsonGenerator(Writer writer) throws IOException;
+
+    protected abstract G createJsonGenerator(OutputStream outputStream) throws IOException;
 
     //properties are very broken across avro versions
 

helper/helper-common/src/main/java/com/linkedin/avroutil1/compatibility/Jackson1JsonGeneratorWrapper.java

@@ -72,4 +72,9 @@ public void writeArrayFieldStart(String fieldName) throws IOException {
     public void flush() throws IOException {
         delegate.flush();
     }
+
+    @Override
+    public void close() throws IOException {
+        delegate.close();
+    }
 }

helper/helper-common/src/main/java/com/linkedin/avroutil1/compatibility/Jackson2JsonGeneratorWrapper.java

@@ -72,4 +72,9 @@ public void writeArrayFieldStart(String fieldName) throws IOException {
     public void flush() throws IOException {
         delegate.flush();
     }
+
+    @Override
+    public void close() throws IOException {
+        delegate.close();
+    }
 }

helper/helper-common/src/main/java/com/linkedin/avroutil1/compatibility/JsonGeneratorWrapper.java

@@ -11,7 +11,7 @@
 /**
  * internal abstraction to bridge jackson 1 to 2 JsonGenerator
  */
-public interface JsonGeneratorWrapper<T> {
+public interface JsonGeneratorWrapper<T> extends AutoCloseable {
 
     T getDelegate();
 
@@ -34,4 +34,6 @@ public interface JsonGeneratorWrapper<T> {
     void writeArrayFieldStart(String fieldName) throws IOException;
 
     void flush() throws IOException;
+
+    void close() throws IOException;
 }

helper/helper/src/main/java/com/linkedin/avroutil1/compatibility/AvroCompatibilityHelper.java

@@ -23,6 +23,7 @@
 import java.io.ObjectOutput;
 import java.io.OutputStream;
 import java.io.StringWriter;
+import java.io.Writer;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;
 import java.lang.reflect.Method;
@@ -1140,6 +1141,54 @@ public static String toAvsc(Schema schema, AvscGenerationConfig config) {
     return ADAPTER.toAvsc(schema, config);
   }
 
+  /**
+   * Given a schema, writes a (exploded, fully-inlined, self-contained, however you want to call it)
+   * avsc representation of the schema to the given {@link java.io.Writer}.
+   *
+   * This is logically the same as {@link Schema#toString(boolean)} except not full of horrible bugs.
+   * specifically, under all versions of avro, we support:
+   * <ul>
+   *     <li>output free of avro-702, even under avro 1.4</li>
+   *     <li>escaped characters in docs and default values remain properly escaped (avro-886)</li>
+   * </ul>
+   * (unless of course you choose to delegate to vanilla avro, at which point youre at the mercy of
+   * the runtime version thereof)
+   * @param schema a schema to serialize to avsc
+   * @param config configuration for avsc generation. see {@link AvscGenerationConfig} for available knobs
+   * @param writer The writer to write to.
+   */
+  public static void writeAvsc(Schema schema, AvscGenerationConfig config, Writer writer) {
+    assertAvroAvailable();
+    if (config == null) {
+      throw new IllegalArgumentException("config must be provided");
+    }
+    ADAPTER.writeAvsc(schema, config, writer);
+  }
+
+  /**
+   * Given a schema, writes a (exploded, fully-inlined, self-contained, however you want to call it)
+   * avsc representation of the schema to the given {@link java.io.OutputStream}.
+   *
+   * This is logically the same as {@link Schema#toString(boolean)} except not full of horrible bugs.
+   * specifically, under all versions of avro, we support:
+   * <ul>
+   *     <li>output free of avro-702, even under avro 1.4</li>
+   *     <li>escaped characters in docs and default values remain properly escaped (avro-886)</li>
+   * </ul>
+   * (unless of course you choose to delegate to vanilla avro, at which point youre at the mercy of
+   * the runtime version thereof)
+   * @param schema a schema to serialize to avsc
+   * @param config configuration for avsc generation. see {@link AvscGenerationConfig} for available knobs
+   * @param stream The output stream to write to.
+   */
+  public static void writeAvsc(Schema schema, AvscGenerationConfig config, OutputStream stream) {
+    assertAvroAvailable();
+    if (config == null) {
+      throw new IllegalArgumentException("config must be provided");
+    }
+    ADAPTER.writeAvsc(schema, config, stream);
+  }
+
   /***
    * Check if Fields in schema are reordered
    * @param schema

helper/impls/helper-impl-110/src/main/java/com/linkedin/avroutil1/compatibility/avro110/Avro110Adapter.java

@@ -31,6 +31,8 @@
 import com.linkedin.avroutil1.compatibility.avro110.codec.CompatibleJsonEncoder;
 import com.linkedin.avroutil1.compatibility.backports.ObjectInputToInputStreamAdapter;
 import com.linkedin.avroutil1.normalization.AvscWriterPlugin;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import org.apache.avro.AvroRuntimeException;
 import org.apache.avro.JsonProperties;
 import org.apache.avro.Schema;
@@ -491,7 +493,7 @@ public Schema newEnumSchema(String name, String doc, String namespace, List<Stri
   }
 
   @Override
-  public String toAvsc(Schema schema, AvscGenerationConfig config) {
+  public void writeAvsc(Schema schema, AvscGenerationConfig config, Writer writer) {
     boolean useRuntime;
     if (!isRuntimeAvroCapableOf(config)) {
       if (config.isForceUseOfRuntimeAvro()) {
@@ -505,13 +507,46 @@ public String toAvsc(Schema schema, AvscGenerationConfig config) {
     }
 
     if (useRuntime) {
-      return schema.toString(config.isPrettyPrint());
+      try {
+        writer.write(schema.toString(config.isPrettyPrint()));
+      } catch (IOException e) {
+        throw new AvroRuntimeException(e);
+      }
+    } else {
+      //if the user does not specify do whatever runtime avro would (which for 1.10 means produce correct schema)
+      boolean usePre702Logic = config.getRetainPreAvro702Logic().orElse(Boolean.FALSE);
+      Avro110AvscWriter avscWriter =
+          new Avro110AvscWriter(config.isPrettyPrint(), usePre702Logic, config.isAddAvro702Aliases());
+      avscWriter.writeAvsc(schema, writer);
+    }
+  }
+
+  @Override
+  public void writeAvsc(Schema schema, AvscGenerationConfig config, OutputStream stream) {
+    boolean useRuntime;
+    if (!isRuntimeAvroCapableOf(config)) {
+      if (config.isForceUseOfRuntimeAvro()) {
+        throw new UnsupportedOperationException(
+            "desired configuration " + config + " is forced yet runtime avro " + supportedMajorVersion()
+                + " is not capable of it");
+      }
+      useRuntime = false;
+    } else {
+      useRuntime = config.isPreferUseOfRuntimeAvro();
+    }
+
+    if (useRuntime) {
+      try {
+        stream.write(schema.toString(config.isPrettyPrint()).getBytes(StandardCharsets.UTF_8));
+      } catch (IOException e) {
+        throw new AvroRuntimeException(e);
+      }
     } else {
       //if the user does not specify do whatever runtime avro would (which for 1.10 means produce correct schema)
       boolean usePre702Logic = config.getRetainPreAvro702Logic().orElse(Boolean.FALSE);
-      Avro110AvscWriter writer =
+      Avro110AvscWriter avscWriter =
           new Avro110AvscWriter(config.isPrettyPrint(), usePre702Logic, config.isAddAvro702Aliases());
-      return writer.toAvsc(schema);
+      avscWriter.writeAvsc(schema, stream);
     }
   }
 

helper/impls/helper-impl-110/src/main/java/com/linkedin/avroutil1/compatibility/avro110/Avro110AvscWriter.java

@@ -15,7 +15,8 @@
 import com.linkedin.avroutil1.compatibility.Jackson2Utils;
 import com.linkedin.avroutil1.normalization.AvscWriterPlugin;
 import java.io.IOException;
-import java.io.StringWriter;
+import java.io.OutputStream;
+import java.io.Writer;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -51,12 +52,22 @@ public Avro110AvscWriter(boolean pretty, boolean preAvro702, boolean addAliasesF
     }
 
     @Override
-    protected Jackson2JsonGeneratorWrapper createJsonGenerator(StringWriter writer) throws IOException {
+    protected Jackson2JsonGeneratorWrapper createJsonGenerator(Writer writer) throws IOException {
         JsonGenerator gen = FACTORY.createGenerator(writer);
+        return createWrapper(gen);
+    }
+
+    @Override
+    protected Jackson2JsonGeneratorWrapper createJsonGenerator(OutputStream stream) throws IOException {
+        JsonGenerator gen = FACTORY.createGenerator(stream);
+        return createWrapper(gen);
+    }
+
+    private Jackson2JsonGeneratorWrapper createWrapper(JsonGenerator generator) {
         if (pretty) {
-            gen.useDefaultPrettyPrinter();
+            generator.useDefaultPrettyPrinter();
         }
-        return new Jackson2JsonGeneratorWrapper(gen);
+        return new Jackson2JsonGeneratorWrapper(generator);
     }
 
     @Override

helper/impls/helper-impl-111/src/main/java/com/linkedin/avroutil1/compatibility/avro111/Avro111Adapter.java

@@ -31,6 +31,8 @@
 import com.linkedin.avroutil1.compatibility.avro111.codec.CompatibleJsonEncoder;
 import com.linkedin.avroutil1.compatibility.backports.ObjectInputToInputStreamAdapter;
 import com.linkedin.avroutil1.normalization.AvscWriterPlugin;
+import java.io.Writer;
+import java.nio.charset.StandardCharsets;
 import org.apache.avro.AvroRuntimeException;
 import org.apache.avro.JsonProperties;
 import org.apache.avro.Schema;
@@ -489,7 +491,7 @@ public Schema newEnumSchema(String name, String doc, String namespace, List<Stri
   }
 
   @Override
-  public String toAvsc(Schema schema, AvscGenerationConfig config) {
+  public void writeAvsc(Schema schema, AvscGenerationConfig config, Writer writer) {
     boolean useRuntime;
     if (!isRuntimeAvroCapableOf(config)) {
       if (config.isForceUseOfRuntimeAvro()) {
@@ -503,16 +505,50 @@ public String toAvsc(Schema schema, AvscGenerationConfig config) {
     }
 
     if (useRuntime) {
-      return schema.toString(config.isPrettyPrint());
+      try {
+        writer.write(schema.toString(config.isPrettyPrint()));
+      } catch (IOException e) {
+        throw new AvroRuntimeException(e);
+      }
+    } else {
+      //if the user does not specify do whatever runtime avro would (which for 1.11 means produce correct schema)
+      boolean usePre702Logic = config.getRetainPreAvro702Logic().orElse(Boolean.FALSE);
+      Avro111AvscWriter avscWriter =
+          new Avro111AvscWriter(config.isPrettyPrint(), usePre702Logic, config.isAddAvro702Aliases());
+      avscWriter.writeAvsc(schema, writer);
+    }
+  }
+
+  @Override
+  public void writeAvsc(Schema schema, AvscGenerationConfig config, OutputStream stream) {
+    boolean useRuntime;
+    if (!isRuntimeAvroCapableOf(config)) {
+      if (config.isForceUseOfRuntimeAvro()) {
+        throw new UnsupportedOperationException(
+            "desired configuration " + config + " is forced yet runtime avro " + supportedMajorVersion()
+                + " is not capable of it");
+      }
+      useRuntime = false;
+    } else {
+      useRuntime = config.isPreferUseOfRuntimeAvro();
+    }
+
+    if (useRuntime) {
+      try {
+        stream.write(schema.toString(config.isPrettyPrint()).getBytes(StandardCharsets.UTF_8));
+      } catch (IOException e) {
+        throw new AvroRuntimeException(e);
+      }
     } else {
       //if the user does not specify do whatever runtime avro would (which for 1.11 means produce correct schema)
       boolean usePre702Logic = config.getRetainPreAvro702Logic().orElse(Boolean.FALSE);
-      Avro111AvscWriter writer =
+      Avro111AvscWriter avscWriter =
           new Avro111AvscWriter(config.isPrettyPrint(), usePre702Logic, config.isAddAvro702Aliases());
-      return writer.toAvsc(schema);
+      avscWriter.writeAvsc(schema, stream);
     }
   }
 
+
   @Override
   public AvscWriter getAvscWriter(AvscGenerationConfig config, List<AvscWriterPlugin> schemaPlugins) {
     boolean usePre702Logic = config.getRetainPreAvro702Logic().orElse(Boolean.FALSE);