Share multipart framing and headers with Kotlin Multiplatform

.github/workflows/test-kmp.yml

@@ -33,6 +33,11 @@ on:
       - 'packages/react-native/ReactCommon/react/utils/FloatComparison.h'
       - 'packages/react-native/ReactCommon/react/utils/ManagedObjectWrapper.*'
       - 'packages/react-native/React/React-RCTFabric.podspec'
+      - 'packages/react-native/React-Core.podspec'
+      - 'packages/react-native/React/Base/RCTMultipartStreamReader.*'
+      - 'packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/MultipartStreamReader.kt'
+      - 'packages/react-native/ReactAndroid/src/test/java/com/facebook/react/devsupport/MultipartStreamReaderTest.kt'
+      - 'packages/rn-tester/RNTesterUnitTests/RCTMultipartStreamReaderTests.m'
       - 'packages/react-native/scripts/react_native_pods.rb'
       - 'packages/react-native/scripts/cocoapods/kmp.rb'
       - 'packages/react-native/Package.swift'
@@ -72,6 +77,11 @@ on:
       - 'packages/react-native/ReactCommon/react/utils/FloatComparison.h'
       - 'packages/react-native/ReactCommon/react/utils/ManagedObjectWrapper.*'
       - 'packages/react-native/React/React-RCTFabric.podspec'
+      - 'packages/react-native/React-Core.podspec'
+      - 'packages/react-native/React/Base/RCTMultipartStreamReader.*'
+      - 'packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/MultipartStreamReader.kt'
+      - 'packages/react-native/ReactAndroid/src/test/java/com/facebook/react/devsupport/MultipartStreamReaderTest.kt'
+      - 'packages/rn-tester/RNTesterUnitTests/RCTMultipartStreamReaderTests.m'
       - 'packages/react-native/scripts/react_native_pods.rb'
       - 'packages/react-native/scripts/cocoapods/kmp.rb'
       - 'packages/react-native/Package.swift'
@@ -92,6 +102,10 @@ jobs:
     steps:
       - name: Checkout
         uses: actions/checkout@v6
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
       - name: Set up JDK 17
         uses: actions/setup-java@v5
         with:
@@ -135,6 +149,12 @@ jobs:
         env:
           RCT_KMP_BUILD_TYPE: Release
         run: ./scripts/test-apple-gradient.sh
+      - name: Compare native and shared multipart adapters
+        if: ${{ !cancelled() && steps.shared.outcome == 'success' }}
+        working-directory: packages/react-native/ReactShared
+        run: |
+          ./scripts/test-apple-multipart.sh
+          python3 scripts/test-android-multipart.py --max-workers 2
       - name: Test packaged XCFramework consumption
         if: ${{ !cancelled() && steps.shared.outcome == 'success' }}
         working-directory: packages/react-native/ReactShared
@@ -159,6 +179,8 @@ jobs:
           path: |
             packages/react-native/ReactShared/build/reports/tests
             packages/react-native/ReactShared/build/test-results
+            packages/react-native/ReactShared/build/apple-multipart-test/**/*.log
+            packages/react-native/ReactShared/build/android-multipart-test/build/test-results
             packages/react-native/ReactShared/build/apple-distribution/**/*.json
             packages/react-native/ReactShared/build/apple-distribution/**/*.log
             packages/react-native/ReactShared/build/apple-distribution/**/consumer.xcresult

packages/react-native/React-Core.podspec

@@ -7,6 +7,10 @@ require "json"
 
 package = JSON.parse(File.read(File.join(__dir__, "package.json")))
 version = package['version']
+kmp_enabled = ENV['RCT_USE_KMP'] == '1'
+if kmp_enabled && ENV['RCT_USE_PREBUILT_RNCORE'] != '0'
+  raise 'RCT_USE_KMP=1 requires React Native core source builds. Use use_react_native! or set RCT_USE_PREBUILT_RNCORE=0.'
+end
 
 source = { :git => 'https://github.com/facebook/react-native.git' }
 if version == '1000.0.0'
@@ -54,13 +58,25 @@ Pod::Spec.new do |s|
   s.compiler_flags         = js_engine_flags()
   s.header_dir             = "React"
   s.weak_framework         = "JavaScriptCore"
-  s.pod_target_xcconfig    = {
+  pod_target_xcconfig     = {
                                "HEADER_SEARCH_PATHS" => header_search_paths,
                                "DEFINES_MODULE" => "YES",
                                "GCC_PREPROCESSOR_DEFINITIONS" => "RCT_METRO_PORT=${RCT_METRO_PORT}",
                                "CLANG_CXX_LANGUAGE_STANDARD" => rct_cxx_language_standard(),
                                "FRAMEWORK_SEARCH_PATHS" => frameworks_search_paths.join(" ")
                              }
+  if kmp_enabled
+    s.dependency 'React-KMP'
+    # React-Core is the common dependency of all Apple consumers. With dynamic
+    # pods it owns the Kotlin runtime once, even before Core calls a shared API.
+    # Static builds link the archive in the application via the post-install helper.
+    %w[iphoneos iphonesimulator].each do |sdk|
+      pod_target_xcconfig["GCC_PREPROCESSOR_DEFINITIONS[sdk=#{sdk}*]"] = '$(inherited) RCT_USE_KMP=1'
+      pod_target_xcconfig["FRAMEWORK_SEARCH_PATHS[sdk=#{sdk}*]"] = '$(inherited) "$(PODS_CONFIGURATION_BUILD_DIR)/ReactNativeSharedKMP"'
+      pod_target_xcconfig["OTHER_LDFLAGS[sdk=#{sdk}*]"] = '$(inherited) -ObjC -framework ReactNativeShared'
+    end
+  end
+  s.pod_target_xcconfig = pod_target_xcconfig
   s.user_target_xcconfig   = { "HEADER_SEARCH_PATHS" => "\"$(PODS_ROOT)/Headers/Private/React-Core\""}
   s.default_subspec        = "Default"
 

packages/react-native/React/Base/RCTMultipartStreamReader.m

@@ -7,6 +7,14 @@
 
 #import "RCTMultipartStreamReader.h"
 #import <QuartzCore/QuartzCore.h>
+#import <TargetConditionals.h>
+
+#if RCT_USE_KMP && TARGET_OS_IOS && !TARGET_OS_MACCATALYST
+#define RCT_MULTIPART_USE_KMP 1
+#import <ReactNativeShared/ReactNativeShared.h>
+#else
+#define RCT_MULTIPART_USE_KMP 0
+#endif
 
 #define CRLF @"\r\n"
 
@@ -30,6 +38,12 @@ - (NSDictionary *)parseHeaders:(NSData *)data
 {
   NSMutableDictionary *headers = [NSMutableDictionary new];
   NSString *text = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
+#if RCT_MULTIPART_USE_KMP
+  for (RNSMultipartHeader *header in [RNSMultipartHeaders.shared parseText:text ?: @""]) {
+    NSString *value = [header.value stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
+    [headers setValue:value forKey:header.name];
+  }
+#else
   NSArray<NSString *> *lines = [text componentsSeparatedByString:CRLF];
   for (NSString *line in lines) {
     NSUInteger location = [line rangeOfString:@":"].location;
@@ -41,6 +55,7 @@ - (NSDictionary *)parseHeaders:(NSData *)data
         stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceAndNewlineCharacterSet]];
     [headers setValue:value forKey:key];
   }
+#endif
   return headers;
 }
 
@@ -84,13 +99,17 @@ - (void)emitProgress:(NSDictionary *)headers
 - (BOOL)readAllPartsWithCompletionCallback:(RCTMultipartCallback)callback
                           progressCallback:(RCTMultipartProgressCallback)progressCallback
 {
-  NSInteger chunkStart = 0;
-  NSInteger bytesSeen = 0;
-
   NSData *delimiter =
       [[NSString stringWithFormat:@"%@--%@%@", CRLF, _boundary, CRLF] dataUsingEncoding:NSUTF8StringEncoding];
   NSData *closeDelimiter =
       [[NSString stringWithFormat:@"%@--%@--%@", CRLF, _boundary, CRLF] dataUsingEncoding:NSUTF8StringEncoding];
+#if RCT_MULTIPART_USE_KMP
+  RNSMultipartFraming *framing = [[RNSMultipartFraming alloc] initWithDelimiterLength:(int32_t)delimiter.length
+                                                                 closeDelimiterLength:(int32_t)closeDelimiter.length];
+#else
+  NSInteger chunkStart = 0;
+  NSInteger bytesSeen = 0;
+#endif
   NSMutableData *content = [[NSMutableData alloc] initWithCapacity:1];
   NSDictionary *currentHeaders = nil;
   NSUInteger currentHeadersLength = 0;
@@ -101,9 +120,13 @@ - (BOOL)readAllPartsWithCompletionCallback:(RCTMultipartCallback)callback
   [_stream open];
   while (true) {
     BOOL isCloseDelimiter = NO;
-    // Search only a subset of chunk that we haven't seen before + few bytes
-    // to allow for the edge case when the delimiter is cut by read call
+#if RCT_MULTIPART_USE_KMP
+    NSInteger searchStart = [framing searchStartBufferOffset:0];
+    NSInteger chunkStart = [framing partStartBufferOffset:0];
+#else
+    // Preserve overlap when a delimiter is split between reads.
     NSInteger searchStart = MAX(bytesSeen - (NSInteger)closeDelimiter.length, chunkStart);
+#endif
     NSRange remainingBufferRange = NSMakeRange(searchStart, content.length - searchStart);
 
     // Check for delimiters.
@@ -113,6 +136,14 @@ - (BOOL)readAllPartsWithCompletionCallback:(RCTMultipartCallback)callback
       range = [content rangeOfData:closeDelimiter options:0 range:remainingBufferRange];
     }
 
+#if RCT_MULTIPART_USE_KMP
+    NSInteger index = range.location == NSNotFound ? -1 : (NSInteger)range.location;
+    RNSMultipartChunk *chunk = [framing nextChunkBufferLength:content.length
+                                                 bufferOffset:0
+                                               delimiterIndex:isCloseDelimiter ? -1 : index
+                                          closeDelimiterIndex:isCloseDelimiter ? index : -1];
+#endif
+
     if (range.location == NSNotFound) {
       if (currentHeaders == nil) {
         // Check for the headers delimiter.
@@ -131,7 +162,9 @@ - (BOOL)readAllPartsWithCompletionCallback:(RCTMultipartCallback)callback
                   callback:progressCallback];
       }
 
+#if !RCT_MULTIPART_USE_KMP
       bytesSeen = content.length;
+#endif
       NSInteger bytesRead = [_stream read:buffer maxLength:bufferLen];
       if (bytesRead <= 0 || _stream.streamError) {
         return NO;
@@ -140,12 +173,19 @@ - (BOOL)readAllPartsWithCompletionCallback:(RCTMultipartCallback)callback
       continue;
     }
 
+#if RCT_MULTIPART_USE_KMP
+    NSInteger chunkEnd = chunk.end;
+    BOOL isPart = chunk.isPart;
+    isCloseDelimiter = chunk.isLast;
+#else
     NSInteger chunkEnd = range.location;
-    NSInteger length = chunkEnd - chunkStart;
+    BOOL isPart = chunkStart > 0;
     bytesSeen = chunkEnd;
+#endif
+    NSInteger length = chunkEnd - chunkStart;
 
     // Ignore preamble
-    if (chunkStart > 0) {
+    if (isPart) {
       NSData *chunk = [content subdataWithRange:NSMakeRange(chunkStart, length)];
       [self emitProgress:currentHeaders
            contentLength:chunk.length - currentHeadersLength
@@ -160,7 +200,9 @@ - (BOOL)readAllPartsWithCompletionCallback:(RCTMultipartCallback)callback
       return YES;
     }
 
+#if !RCT_MULTIPART_USE_KMP
     chunkStart = chunkEnd + delimiter.length;
+#endif
   }
 }
 

packages/react-native/React/React-RCTFabric.podspec

@@ -69,8 +69,6 @@ Pod::Spec.new do |s|
       'GCC_PREPROCESSOR_DEFINITIONS[sdk=iphonesimulator*]' => '$(inherited) RCT_USE_KMP=1',
       'FRAMEWORK_SEARCH_PATHS[sdk=iphoneos*]' => '$(inherited) "$(PODS_CONFIGURATION_BUILD_DIR)/ReactNativeSharedKMP"',
       'FRAMEWORK_SEARCH_PATHS[sdk=iphonesimulator*]' => '$(inherited) "$(PODS_CONFIGURATION_BUILD_DIR)/ReactNativeSharedKMP"',
-      'OTHER_LDFLAGS[sdk=iphoneos*]' => '$(inherited) -framework ReactNativeShared',
-      'OTHER_LDFLAGS[sdk=iphonesimulator*]' => '$(inherited) -framework ReactNativeShared',
     })
   end
   s.pod_target_xcconfig = pod_target_xcconfig

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/devsupport/MultipartStreamReader.kt

@@ -9,6 +9,8 @@
 
 package com.facebook.react.devsupport
 
+import com.facebook.react.shared.MultipartFraming
+import com.facebook.react.shared.MultipartHeaders
 import java.io.IOException
 import java.util.TreeMap
 import kotlin.math.max
@@ -52,30 +54,22 @@ internal class MultipartStreamReader(
     // throughput and fewer syscalls. For a 2MB bundle: ~128 reads instead of ~512.
     // Memory impact is negligible (12KB increase) while I/O overhead is significantly reduced.
     val bufferLen = 16 * 1024
-    var chunkStart: Long = 0
-    var bytesSeen: Long = 0
+    val framing = MultipartFraming(delimiter.size(), closeDelimiter.size())
+    var bufferOffset = 0L
     val content = Buffer()
 
     var currentHeaders: Map<String, String>? = null
     var currentBodyStartIndexInContent: Long = -1
 
     while (true) {
-      var isCloseDelimiter = false
-
-      // Search only a subset of chunk that we haven't seen before + few bytes
-      // to allow for the edge case when the delimiter is cut by read call.
-      val searchStart =
-          max((bytesSeen - closeDelimiter.size()).toDouble(), chunkStart.toDouble()).toLong()
-
-      var indexOfDelimiter = content.indexOf(delimiter, searchStart)
-      if (indexOfDelimiter == -1L) {
-        isCloseDelimiter = true
-        indexOfDelimiter = content.indexOf(closeDelimiter, searchStart)
-      }
-
-      if (indexOfDelimiter == -1L) {
-        bytesSeen = content.size()
-
+      val searchStart = framing.searchStart(bufferOffset)
+      val indexOfDelimiter = content.indexOf(delimiter, searchStart)
+      val indexOfCloseDelimiter =
+          if (indexOfDelimiter < 0) content.indexOf(closeDelimiter, searchStart) else -1L
+      val chunk =
+          framing.nextChunk(content.size(), bufferOffset, indexOfDelimiter, indexOfCloseDelimiter)
+
+      if (chunk == null) {
         if (currentHeaders == null) {
           val indexOfHeadersDelimiter = content.indexOf(headersDelimiter, searchStart)
           if (indexOfHeadersDelimiter >= 0) {
@@ -97,44 +91,37 @@ internal class MultipartStreamReader(
         continue
       }
 
-      val chunkEnd = indexOfDelimiter
-      val length = chunkEnd - chunkStart
+      val chunkEnd = chunk.end
+      val length = chunkEnd - chunk.start
 
       // Ignore preamble
-      if (chunkStart > 0) {
+      if (chunk.isPart) {
         if (currentHeaders != null && currentBodyStartIndexInContent >= 0) {
           val loadedFinal = max(0L, chunkEnd - currentBodyStartIndexInContent)
           emitProgress(currentHeaders, loadedFinal, true, listener)
         }
-        content.skip(chunkStart)
-        emitChunk(content, length, isCloseDelimiter, listener)
+        content.skip(chunk.start)
+        emitChunk(content, length, chunk.isLast, listener)
 
         currentHeaders = null
         currentBodyStartIndexInContent = -1
       } else {
         content.skip(chunkEnd)
       }
-      if (isCloseDelimiter) {
+      if (chunk.isLast) {
         return true
       }
-
-      chunkStart = delimiter.size().toLong()
-      bytesSeen = chunkStart
+      bufferOffset += chunkEnd
     }
   }
 
   private fun parseHeaders(data: Buffer): Map<String, String> {
     // Header names are case-insensitive
     val headers: MutableMap<String, String> = TreeMap(String.CASE_INSENSITIVE_ORDER)
     val text = data.readUtf8()
-    val lines = text.split(CRLF.toRegex()).dropLastWhile { it.isEmpty() }.toTypedArray()
-    for (line in lines) {
-      val indexOfSeparator = line.indexOf(":")
-      if (indexOfSeparator == -1) {
-        continue
-      }
-      val key = line.substring(0, indexOfSeparator).trim { it <= ' ' }
-      val value = line.substring(indexOfSeparator + 1).trim { it <= ' ' }
+    for (header in MultipartHeaders.parse(text)) {
+      val key = header.name.trim { it <= ' ' }
+      val value = header.value.trim { it <= ' ' }
       headers[key] = value
     }
     return headers

packages/react-native/ReactAndroid/src/test/java/com/facebook/react/devsupport/MultipartStreamReaderTest.kt

@@ -251,6 +251,56 @@ class MultipartStreamReaderTest {
     }
   }
 
+  @Test
+  fun testHeaderWhitespaceDuplicatesAndColonValues() {
+    val source =
+        Buffer()
+            .writeUtf8(
+                "\r\n--sample\r\n X-Name : first\r\nx-name: second:extra \r\ninvalid\r\n\r\nbody\r\n--sample--\r\n"
+            )
+    var calls = 0
+    assertThat(
+            MultipartStreamReader(source, "sample")
+                .readAllParts(
+                    object : CallCountTrackingChunkCallback() {
+                      override fun onChunkComplete(
+                          headers: Map<String, String>,
+                          body: BufferedSource,
+                          isLastChunk: Boolean,
+                      ) {
+                        calls++
+                        assertThat(headers).hasSize(1)
+                        assertThat(headers["X-Name"]).isEqualTo("second:extra")
+                        assertThat(body.readUtf8()).isEqualTo("body")
+                        assertThat(isLastChunk).isTrue()
+                      }
+                    }
+                )
+        )
+        .isTrue()
+    assertThat(calls).isEqualTo(1)
+  }
+
+  @Test
+  fun testFinalProgressForFragmentedBody() {
+    val body = "x".repeat(64 * 1024)
+    val source =
+        Buffer()
+            .writeUtf8(
+                "\r\n--sample\r\nContent-Length: ${body.length}\r\n\r\n$body\r\n--sample--\r\n"
+            )
+    val progress = mutableListOf<Pair<Long, Long>>()
+    val callback =
+        object : CallCountTrackingChunkCallback() {
+          override fun onChunkProgress(headers: Map<String, String>, loaded: Long, total: Long) {
+            progress.add(loaded to total)
+          }
+        }
+    assertThat(MultipartStreamReader(source, "sample").readAllParts(callback)).isTrue()
+    assertThat(callback.callCount).isEqualTo(1)
+    assertThat(progress.last()).isEqualTo(body.length.toLong() to body.length.toLong())
+  }
+
   internal open class CallCountTrackingChunkCallback : MultipartStreamReader.ChunkListener {
     var callCount = 0
       private set