Increasing the speed of the Robohash SVG to buffer function

app/src/main/java/com/vitorpamplona/amethyst/ui/components/Robohash.kt

@@ -30,9 +30,10 @@ import coil.fetch.Fetcher
 import coil.fetch.SourceResult
 import coil.request.ImageRequest
 import coil.request.Options
+import com.vitorpamplona.amethyst.commons.Robohash
 import com.vitorpamplona.amethyst.service.checkNotInMainThread
-import com.vitorpamplona.quartz.utils.Robohash
-import okio.Buffer
+import okio.buffer
+import okio.source
 import java.nio.charset.Charset
 
 @Stable
@@ -43,14 +44,10 @@ class HashImageFetcher(
 ) : Fetcher {
     override suspend fun fetch(): SourceResult {
         checkNotInMainThread()
+
         val source =
             try {
-                val buffer = Buffer()
-                buffer.writeString(
-                    Robohash.assemble(data.toString(), isLightTheme),
-                    Charset.defaultCharset(),
-                )
-                buffer
+                Robohash.assemble(data.toString(), isLightTheme).byteInputStream(Charset.defaultCharset()).source().buffer()
             } finally {
             }
 

benchmark/src/androidTest/java/com/vitorpamplona/amethyst/benchmark/RobohashBenchmark.kt

@@ -18,16 +18,20 @@
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.vitorpamplona.quartz.benchmark
+package com.vitorpamplona.amethyst.benchmark
 
 import androidx.benchmark.junit4.BenchmarkRule
 import androidx.benchmark.junit4.measureRepeated
 import androidx.test.ext.junit.runners.AndroidJUnit4
-import com.vitorpamplona.quartz.utils.Robohash
+import com.vitorpamplona.amethyst.commons.Robohash
 import junit.framework.TestCase.assertEquals
+import okio.Buffer
+import okio.buffer
+import okio.source
 import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
+import java.nio.charset.Charset
 
 /**
  * Benchmark, which will execute on an Android device.
@@ -41,7 +45,7 @@ class RobohashBenchmark {
 
     val warmHex = "f4f016c739b8ec0d6313540a8b12cf48a72b485d38338627ec9d427583551f9a"
     val testHex = "48a72b485d38338627ec9d427583551f9af4f016c739b8ec0d6313540a8b12cf"
-    val resultingSVG =
+    val expectedTestSVG =
         "<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 300 300\">" +
             "<defs>" +
             "<style>" +
@@ -196,7 +200,26 @@ class RobohashBenchmark {
         Robohash.assemble(warmHex, true)
         benchmarkRule.measureRepeated {
             val result = Robohash.assemble(testHex, true)
-            assertEquals(resultingSVG, result)
+            assertEquals(expectedTestSVG, result)
+        }
+    }
+
+    @Test
+    fun createSVGInBufferCopy() {
+        // warm up
+        Robohash.assemble(warmHex, true)
+        benchmarkRule.measureRepeated {
+            val buffer = Buffer()
+            buffer.writeString(Robohash.assemble(testHex, true), Charset.defaultCharset())
+        }
+    }
+
+    @Test
+    fun createSVGInBufferViaInputStream() {
+        // warm up
+        Robohash.assemble(warmHex, true)
+        benchmarkRule.measureRepeated {
+            Robohash.assemble(testHex, true).byteInputStream(Charset.defaultCharset()).source().buffer()
         }
     }
 }

commons/build.gradle

@@ -35,6 +35,8 @@ android {
 }
 
 dependencies {
+    implementation project(path: ':quartz')
+
     testImplementation 'junit:junit:4.13.2'
     androidTestImplementation 'androidx.test.ext:junit:1.1.5'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'

commons/src/main/java/com/vitorpamplona/amethyst/commons/Robohash.kt

@@ -18,10 +18,9 @@
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */
-package com.vitorpamplona.quartz.utils
+package com.vitorpamplona.amethyst.commons
 
 import android.util.Log
-import androidx.compose.runtime.Immutable
 import com.vitorpamplona.quartz.crypto.CryptoUtils
 import com.vitorpamplona.quartz.encoders.Hex
 import com.vitorpamplona.quartz.encoders.HexValidator
@@ -55,9 +54,7 @@ object Robohash {
     private fun reduce(
         start: Int,
         channel: Byte,
-    ): Int {
-        return (start + (channel.toUByte().toInt() * 0.3906f)).toInt()
-    }
+    ) = (start + (channel.toUByte().toInt() * 0.3906f)).toInt()
 
     private fun bytesToRGB(
         r: Byte,
@@ -85,6 +82,7 @@ object Robohash {
                 Log.w("Robohash", "$msg is not a hex")
                 CryptoUtils.sha256(msg.toByteArray())
             }
+
         val bgColor = bytesToRGB(hash[0], hash[1], hash[2], isLightTheme)
         val fgColor = bytesToRGB(hash[3], hash[4], hash[5], !isLightTheme)
         val body = bodies[byteMod10(hash[6])]
@@ -110,41 +108,42 @@ object Robohash {
                 BACKGROUND.length +
                 END.length
 
-        val result = StringBuilder(capacity)
+        val result =
+            buildString(capacity) {
+                append(HEADER)
 
-        result.append(HEADER)
+                append(".cls-bg{fill:")
+                append(bgColor)
+                append(";}.cls-fill-1{fill:")
+                append(fgColor)
+                append(";}.cls-fill-2{fill:")
+                append(fgColor)
+                append(";}")
 
-        result.append(".cls-bg{fill:")
-        result.append(bgColor)
-        result.append(";}.cls-fill-1{fill:")
-        result.append(fgColor)
-        result.append(";}.cls-fill-2{fill:")
-        result.append(fgColor)
-        result.append(";}")
+                append(body.style)
+                append(face.style)
+                append(eye.style)
+                append(mouth.style)
+                append(accessory.style)
 
-        result.append(body.style)
-        result.append(face.style)
-        result.append(eye.style)
-        result.append(mouth.style)
-        result.append(accessory.style)
+                append(MID)
 
-        result.append(MID)
+                append(BACKGROUND)
+                append(body.paths)
+                append(face.paths)
+                append(eye.paths)
+                append(mouth.paths)
+                append(accessory.paths)
 
-        result.append(BACKGROUND)
-        result.append(body.paths)
-        result.append(face.paths)
-        result.append(eye.paths)
-        result.append(mouth.paths)
-        result.append(accessory.paths)
+                append(END)
+            }
 
-        result.append(END)
+        check(result.length == capacity) { "${result.length} was different from $capacity" }
 
-        val resultStr = result.toString()
-        check(resultStr.length == capacity) { "${resultStr.length} was different from $capacity" }
-        return resultStr
+        return result
     }
 
-    @Immutable private data class Part(val style: String, val paths: String)
+    private data class Part(val style: String, val paths: String)
 
     const val HEADER =
         "<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 300 300\"><defs><style>"