commit 0f9702b1dc03aed39a9377069c63cc7e5690877e Author: sergeych Date: Fri Feb 3 13:10:43 2023 +0100 initial: varing and smarting packing tools diff --git a/.gitignore b/.gitignore new file mode 100644 index 0000000..8ea68f1 --- /dev/null +++ b/.gitignore @@ -0,0 +1,3 @@ +/.gradle/ +/.idea/ +/build/ diff --git a/README.md b/README.md new file mode 100644 index 0000000..2cac10f --- /dev/null +++ b/README.md @@ -0,0 +1,11 @@ +# Binary tools + +> Work in progress not ready to any practical use + +Goals: + +- Efficient binary serialization +- Pack/unpack byte tools +- 2 flavors of space-effecient varint packing +- CRCs and CRC-protected blocks +- Async variants \ No newline at end of file diff --git a/build.gradle.kts b/build.gradle.kts new file mode 100644 index 0000000..6f4a5a8 --- /dev/null +++ b/build.gradle.kts @@ -0,0 +1,60 @@ +plugins { + kotlin("multiplatform") version "1.7.21" +} + +group = "net.sergeych" +version = "0.0.1-SNAPSHOT" + +repositories { + mavenCentral() + mavenLocal() + maven("https://maven.universablockchain.com/") +} + +kotlin { + jvm { + compilations.all { + kotlinOptions.jvmTarget = "1.8" + } + withJava() + testRuns["test"].executionTask.configure { + useJUnitPlatform() + } + } + js(IR) { + browser { + commonWebpackConfig { + cssSupport.enabled = true + } + } + } + val hostOs = System.getProperty("os.name") + val isMingwX64 = hostOs.startsWith("Windows") + val nativeTarget = when { + hostOs == "Mac OS X" -> macosX64("native") + hostOs == "Linux" -> linuxX64("native") + isMingwX64 -> mingwX64("native") + else -> throw GradleException("Host OS is not supported in Kotlin/Native.") + } + + + sourceSets { + val commonMain by getting { + dependencies { + implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.4") + api("net.sergeych:mp_stools:1.3.2") + } + } + val commonTest by getting { + dependencies { + implementation(kotlin("test")) + } + } + val jvmMain by getting + val jvmTest by getting + val jsMain by getting + val jsTest by getting + val nativeMain by getting + val nativeTest by getting + } +} diff --git a/gradle.properties b/gradle.properties new file mode 100644 index 0000000..9dcc3a7 --- /dev/null +++ b/gradle.properties @@ -0,0 +1,2 @@ +kotlin.code.style=official +kotlin.js.compiler=ir diff --git a/gradlew b/gradlew new file mode 100755 index 0000000..1b6c787 --- /dev/null +++ b/gradlew @@ -0,0 +1,234 @@ +#!/bin/sh + +# +# Copyright © 2015-2021 the original authors. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# https://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. +# + +############################################################################## +# +# Gradle start up script for POSIX generated by Gradle. +# +# Important for running: +# +# (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is +# noncompliant, but you have some other compliant shell such as ksh or +# bash, then to run this script, type that shell name before the whole +# command line, like: +# +# ksh Gradle +# +# Busybox and similar reduced shells will NOT work, because this script +# requires all of these POSIX shell features: +# * functions; +# * expansions «$var», «${var}», «${var:-default}», «${var+SET}», +# «${var#prefix}», «${var%suffix}», and «$( cmd )»; +# * compound commands having a testable exit status, especially «case»; +# * various built-in commands including «command», «set», and «ulimit». +# +# Important for patching: +# +# (2) This script targets any POSIX shell, so it avoids extensions provided +# by Bash, Ksh, etc; in particular arrays are avoided. +# +# The "traditional" practice of packing multiple parameters into a +# space-separated string is a well documented source of bugs and security +# problems, so this is (mostly) avoided, by progressively accumulating +# options in "$@", and eventually passing that to Java. +# +# Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS, +# and GRADLE_OPTS) rely on word-splitting, this is performed explicitly; +# see the in-line comments for details. +# +# There are tweaks for specific operating systems such as AIX, CygWin, +# Darwin, MinGW, and NonStop. +# +# (3) This script is generated from the Groovy template +# https://github.com/gradle/gradle/blob/master/subprojects/plugins/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt +# within the Gradle project. +# +# You can find Gradle at https://github.com/gradle/gradle/. +# +############################################################################## + +# Attempt to set APP_HOME + +# Resolve links: $0 may be a link +app_path=$0 + +# Need this for daisy-chained symlinks. +while + APP_HOME=${app_path%"${app_path##*/}"} # leaves a trailing /; empty if no leading path + [ -h "$app_path" ] +do + ls=$( ls -ld "$app_path" ) + link=${ls#*' -> '} + case $link in #( + /*) app_path=$link ;; #( + *) app_path=$APP_HOME$link ;; + esac +done + +APP_HOME=$( cd "${APP_HOME:-./}" && pwd -P ) || exit + +APP_NAME="Gradle" +APP_BASE_NAME=${0##*/} + +# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"' + +# Use the maximum available, or set MAX_FD != -1 to use that value. +MAX_FD=maximum + +warn () { + echo "$*" +} >&2 + +die () { + echo + echo "$*" + echo + exit 1 +} >&2 + +# OS specific support (must be 'true' or 'false'). +cygwin=false +msys=false +darwin=false +nonstop=false +case "$( uname )" in #( + CYGWIN* ) cygwin=true ;; #( + Darwin* ) darwin=true ;; #( + MSYS* | MINGW* ) msys=true ;; #( + NONSTOP* ) nonstop=true ;; +esac + +CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar + + +# Determine the Java command to use to start the JVM. +if [ -n "$JAVA_HOME" ] ; then + if [ -x "$JAVA_HOME/jre/sh/java" ] ; then + # IBM's JDK on AIX uses strange locations for the executables + JAVACMD=$JAVA_HOME/jre/sh/java + else + JAVACMD=$JAVA_HOME/bin/java + fi + if [ ! -x "$JAVACMD" ] ; then + die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." + fi +else + JAVACMD=java + which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. + +Please set the JAVA_HOME variable in your environment to match the +location of your Java installation." +fi + +# Increase the maximum file descriptors if we can. +if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then + case $MAX_FD in #( + max*) + MAX_FD=$( ulimit -H -n ) || + warn "Could not query maximum file descriptor limit" + esac + case $MAX_FD in #( + '' | soft) :;; #( + *) + ulimit -n "$MAX_FD" || + warn "Could not set maximum file descriptor limit to $MAX_FD" + esac +fi + +# Collect all arguments for the java command, stacking in reverse order: +# * args from the command line +# * the main class name +# * -classpath +# * -D...appname settings +# * --module-path (only if needed) +# * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables. + +# For Cygwin or MSYS, switch paths to Windows format before running java +if "$cygwin" || "$msys" ; then + APP_HOME=$( cygpath --path --mixed "$APP_HOME" ) + CLASSPATH=$( cygpath --path --mixed "$CLASSPATH" ) + + JAVACMD=$( cygpath --unix "$JAVACMD" ) + + # Now convert the arguments - kludge to limit ourselves to /bin/sh + for arg do + if + case $arg in #( + -*) false ;; # don't mess with options #( + /?*) t=${arg#/} t=/${t%%/*} # looks like a POSIX filepath + [ -e "$t" ] ;; #( + *) false ;; + esac + then + arg=$( cygpath --path --ignore --mixed "$arg" ) + fi + # Roll the args list around exactly as many times as the number of + # args, so each arg winds up back in the position where it started, but + # possibly modified. + # + # NB: a `for` loop captures its iteration list before it begins, so + # changing the positional parameters here affects neither the number of + # iterations, nor the values presented in `arg`. + shift # remove old arg + set -- "$@" "$arg" # push replacement arg + done +fi + +# Collect all arguments for the java command; +# * $DEFAULT_JVM_OPTS, $JAVA_OPTS, and $GRADLE_OPTS can contain fragments of +# shell script including quotes and variable substitutions, so put them in +# double quotes to make sure that they get re-expanded; and +# * put everything else in single quotes, so that it's not re-expanded. + +set -- \ + "-Dorg.gradle.appname=$APP_BASE_NAME" \ + -classpath "$CLASSPATH" \ + org.gradle.wrapper.GradleWrapperMain \ + "$@" + +# Use "xargs" to parse quoted args. +# +# With -n1 it outputs one arg per line, with the quotes and backslashes removed. +# +# In Bash we could simply go: +# +# readarray ARGS < <( xargs -n1 <<<"$var" ) && +# set -- "${ARGS[@]}" "$@" +# +# but POSIX shell has neither arrays nor command substitution, so instead we +# post-process each arg (as a line of input to sed) to backslash-escape any +# character that might be a shell metacharacter, then use eval to reverse +# that process (while maintaining the separation between arguments), and wrap +# the whole thing up as a single "set" statement. +# +# This will of course break if any of these variables contains a newline or +# an unmatched quote. +# + +eval "set -- $( + printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" | + xargs -n1 | + sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' | + tr '\n' ' ' + )" '"$@"' + +exec "$JAVACMD" "$@" diff --git a/gradlew.bat b/gradlew.bat new file mode 100644 index 0000000..107acd3 --- /dev/null +++ b/gradlew.bat @@ -0,0 +1,89 @@ +@rem +@rem Copyright 2015 the original author or authors. +@rem +@rem Licensed under the Apache License, Version 2.0 (the "License"); +@rem you may not use this file except in compliance with the License. +@rem You may obtain a copy of the License at +@rem +@rem https://www.apache.org/licenses/LICENSE-2.0 +@rem +@rem Unless required by applicable law or agreed to in writing, software +@rem distributed under the License is distributed on an "AS IS" BASIS, +@rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +@rem See the License for the specific language governing permissions and +@rem limitations under the License. +@rem + +@if "%DEBUG%" == "" @echo off +@rem ########################################################################## +@rem +@rem Gradle startup script for Windows +@rem +@rem ########################################################################## + +@rem Set local scope for the variables with windows NT shell +if "%OS%"=="Windows_NT" setlocal + +set DIRNAME=%~dp0 +if "%DIRNAME%" == "" set DIRNAME=. +set APP_BASE_NAME=%~n0 +set APP_HOME=%DIRNAME% + +@rem Resolve any "." and ".." in APP_HOME to make it shorter. +for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi + +@rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. +set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m" + +@rem Find java.exe +if defined JAVA_HOME goto findJavaFromJavaHome + +set JAVA_EXE=java.exe +%JAVA_EXE% -version >NUL 2>&1 +if "%ERRORLEVEL%" == "0" goto execute + +echo. +echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. +echo. +echo Please set the JAVA_HOME variable in your environment to match the +echo location of your Java installation. + +goto fail + +:findJavaFromJavaHome +set JAVA_HOME=%JAVA_HOME:"=% +set JAVA_EXE=%JAVA_HOME%/bin/java.exe + +if exist "%JAVA_EXE%" goto execute + +echo. +echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% +echo. +echo Please set the JAVA_HOME variable in your environment to match the +echo location of your Java installation. + +goto fail + +:execute +@rem Setup the command line + +set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar + + +@rem Execute Gradle +"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %* + +:end +@rem End local scope for the variables with windows NT shell +if "%ERRORLEVEL%"=="0" goto mainEnd + +:fail +rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of +rem the _cmd.exe /c_ return code! +if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1 +exit /b 1 + +:mainEnd +if "%OS%"=="Windows_NT" endlocal + +:omega diff --git a/settings.gradle.kts b/settings.gradle.kts new file mode 100644 index 0000000..6cf7e03 --- /dev/null +++ b/settings.gradle.kts @@ -0,0 +1,3 @@ + +rootProject.name = "mp_bintools" + diff --git a/src/commonMain/kotlin/net.sergeych.bintools/DataSink.kt b/src/commonMain/kotlin/net.sergeych.bintools/DataSink.kt new file mode 100644 index 0000000..76c9724 --- /dev/null +++ b/src/commonMain/kotlin/net.sergeych.bintools/DataSink.kt @@ -0,0 +1,27 @@ +package net.sergeych.bintools + +abstract class DataSink { + + abstract fun writeByte(data: Byte) + + fun writeByte(data: Int) = writeByte(data.toByte()) + + open fun writeUByte(data: UByte) { + writeByte(data.toByte()) + } + + @Suppress("unused") + open fun writeBytes(data: ByteArray) { + for(d in data) writeByte(d) + } +} + +class ArrayDataSink : DataSink() { + private val result = mutableListOf() + + override fun writeByte(data: Byte) { + result.add(data) + } + + fun toByteArray() = result.toByteArray() +} diff --git a/src/commonMain/kotlin/net.sergeych.bintools/DataSource.kt b/src/commonMain/kotlin/net.sergeych.bintools/DataSource.kt new file mode 100644 index 0000000..4338e2e --- /dev/null +++ b/src/commonMain/kotlin/net.sergeych.bintools/DataSource.kt @@ -0,0 +1,30 @@ +package net.sergeych.bintools + +/** + * data input stream-like abstraction. We need it because + * kotlinx serialization is synchronous and there us nothing + * like multiplatform version of DataInput + * + */ +abstract class DataSource { + + abstract fun readByte(): Byte + + abstract val position: Int + + open fun readUByte() = readByte().toUByte() + + @Suppress("unused") + open fun readBytes(size: Int): ByteArray = + ByteArray(size).also { a -> + for( i in 0..size) + a[i] = readByte() + } +} + +fun ByteArray.toDataSource(): DataSource = + object : DataSource() { + override var position = 0 + + override fun readByte(): Byte = this@toDataSource[position++] + } \ No newline at end of file diff --git a/src/commonMain/kotlin/net.sergeych.bintools/errors.kt b/src/commonMain/kotlin/net.sergeych.bintools/errors.kt new file mode 100644 index 0000000..fa68b16 --- /dev/null +++ b/src/commonMain/kotlin/net.sergeych.bintools/errors.kt @@ -0,0 +1,4 @@ +package net.sergeych.bintools + +class FormatException(message: String="invalid format",cause: Throwable?=null): + Exception(message, cause) \ No newline at end of file diff --git a/src/commonMain/kotlin/net.sergeych.bintools/simple_codecs.kt b/src/commonMain/kotlin/net.sergeych.bintools/simple_codecs.kt new file mode 100644 index 0000000..a66a877 --- /dev/null +++ b/src/commonMain/kotlin/net.sergeych.bintools/simple_codecs.kt @@ -0,0 +1,135 @@ +package net.sergeych.bintools + + +fun longToBytes(value: Long): ByteArray { + var l = value + val result = ByteArray(8) + for (i in 7 downTo 0) { + result[i] = (l and 0xFF).toByte() + l = l shr 8 + } + return result +} + +/** + * Convert 8 bytes to LE long + */ +fun bytesToLong(b: ByteArray): Long { + var result: Long = 0 + for (i in 0 until 8) { + result = result shl 8 + result = result or (b[i].toLong() and 0xFF) + } + return result +} + + +private val hexDigits = "0123456789ABCDEF" + +fun Long.encodeToHex(length: Int = 0): String { + var result = "" + var value = this + if (value < 0) throw IllegalArgumentException("cant convert to hex negative (ambiguous)") + do { + result = hexDigits[(value and 0x0f).toInt()] + result + value = value shr 4 + } while (value > 0) + while (result.length < length) result = "0" + result + return result +} + +fun Int.encodeToHex(length: Int = 0) = (toLong() and 0xFFFFffff).encodeToHex(length) +@Suppress("unused") +fun UInt.encodeToHex(length: Int = 0) = toLong().encodeToHex(length) +fun Byte.encodeToHex(length: Int = 0) = (toLong() and 0xFF).encodeToHex(length) +fun UByte.encodeToHex(length: Int = 0) = toLong().encodeToHex(length) +@Suppress("unused") +fun ULong.encodeToHex(length: Int = 0) = toLong().encodeToHex(length) + +fun ByteArray.encodeToHex(separator: String = " "): String = joinToString(separator) { it.toUByte().encodeToHex(2) } +fun Collection.encodeToHex(separator: String = " "): String = joinToString(separator) { it.toUByte().encodeToHex(2) } + +fun ByteArray.toDump(wide: Boolean = false): String = toDumpLines(wide).joinToString("\n") + +fun ByteArray.toDumpLines(wide: Boolean = false): List { + + val lineSize = if (wide) 32 else 16 + + fun dumpChars(_from: Int): String { + var from = _from + val b = StringBuilder(22) + + b.append('|') + val max: Int = kotlin.math.min(size, from + lineSize) + while (from < max) { + val ch = this[from++].toInt() + if (ch >= ' '.code && ch < 127) b.append(ch.toChar()) else b.append('.') + } + val remainder = from % lineSize + if (remainder > 0) { + var cnt = lineSize - remainder + while (cnt-- > 0) b.append(' ') + } + return b.append("|").toString() + } + + + val lines = mutableListOf() + if (size == 0) return lines + var line: StringBuilder? = null + + if (size != 0) { + for (i in indices) { + if (i % lineSize == 0) { + if (line != null) { + line.append(dumpChars(i - lineSize)) + lines.add(line.toString()) + } + line = StringBuilder(i.encodeToHex(4)) + line.append(' ') + } + line!!.append((this[i].toUByte()).encodeToHex(2)) + line.append(' ') + } + if (line != null) { + val l = size + var fill = lineSize - l % lineSize + if (fill < lineSize) while (fill-- > 0) line.append(" ") + val index = l - l % lineSize + line.append(dumpChars(if (index < l) index else l - lineSize)) + lines.add(line.toString()) + } + } + return lines +} + +fun String.decodeHex(): ByteArray { + val source = this.trim().uppercase() + val result = arrayListOf() + var pos = 0 + while (pos < source.length) { + val i = hexDigits.indexOf(source[pos++]) + if (i < 0) throw FormatException("invalid hex digit in ${source} at ${pos - 1}") + if (pos >= source.length) throw FormatException( + "hex string must consist of bytes " + + "(unexepced end of data): $source" + ) + val j = hexDigits.indexOf(source[pos++]) + if (j < 0) throw FormatException("invalid hex digit in ${source} at ${pos - 1}") + result.add(((i shl 4) or j).toByte()) + while (pos < source.length && (source[pos].isWhitespace())) pos++ + } + return result.toByteArray() +} + +fun ByteArray.flipSelf() { + var i = 0 + var j = size - 1 + while (i < j) { + val x = this[i] + this[i++] = this[j] + this[j--] = x + } +} + +fun ByteArray.flip(): ByteArray = copyOf().also { it.flipSelf() } diff --git a/src/commonMain/kotlin/net.sergeych.bintools/smartint.kt b/src/commonMain/kotlin/net.sergeych.bintools/smartint.kt new file mode 100644 index 0000000..8ff7623 --- /dev/null +++ b/src/commonMain/kotlin/net.sergeych.bintools/smartint.kt @@ -0,0 +1,150 @@ +@file:OptIn(ExperimentalUnsignedTypes::class) + +package com.icodici.ubdata + +import net.sergeych.bintools.ArrayDataSink +import net.sergeych.bintools.DataSink +import net.sergeych.bintools.DataSource +import net.sergeych.bintools.toDataSource + +/** + * Smart variable-length long encoding tools, async. + * + * | Bytes sz | varint bits | smartint bits | + * |:-----:|:------:|:---------:| + * | 1 | 7 | 6 | + * | 2 | 14 | 14 | + * | 3 | 21 | 22 | + * | 4 | 28 | 29 | + * | 5 | 35 | 36 | + * | 6+ | 7*N | 7*N+1 | + * | 9 | 63 | 64 | + * | 10 | 64 | --- | + * + * In other words, except for very small numbers smartint + * gives 1 bit gain. So, full sized 64 bits with smartint takes + * 9 bytes, while varint needs 10. This could be important. + * + * Encoding is the following: + * + * Byte 0: bits 0..1 : type + * bits 2..7 : v0 + * + * Then depending on the type: + * + * type = 0: + * v0 is the resul 0..64 (or -32..32) + * + * type = 1: + * v0, v1 is the result, 14 bits + * + * type = 2: + * v0, v1, v2 are the result, 22bits + * + * type = 3: + * v0, v1, v2, varint encoded + * + * Varint encodes bytes with last bit reserved as end + * flag and first 7 bits are data bits. Last bit 0 means end of the + * sequence. + * + */ +object Smartint { + + private val v0limit: ULong = (1L shl 6).toULong() + private val v1limit = (1L shl 14).toULong() + private val v2limit = (1L shl 22).toULong() + + fun encode(value: ULong, sink: DataSink) { + when { + value < v0limit -> encodeSeq(sink, 0, value) + + value < v1limit -> encodeSeq( + sink, + 1, + value and 0x3Fu, + value shr 6 + ) + + value < v2limit -> encodeSeq( + sink, + 2, + value and 0x3Fu, + (value shr 6) and 0xFFu, + (value shr 14) and 0xFFu, + ) + + else -> { + encodeSeq( + sink, + 3, + value and 0x3Fu, + (value shr 6) and 0xFFu, + (value shr 14) and 0xFFu, + ) + Varint.encode(value shr 22, sink) + } + } + } + + private fun encodeSeq(sink: DataSink, type: Int, vararg bytes: ULong) { + if (bytes.size == 0) + sink.writeByte(0) + else { + if (bytes[0] > v0limit) throw IllegalArgumentException("first number is too big") + sink.writeUByte(((type and 0x03) or (bytes[0] shl 2).toInt()).toUByte()) + for (x in bytes.drop(1)) + sink.writeUByte(x.toUByte()) + } + } + + fun decode(source: DataSource): ULong { + fun get(): ULong = source.readUByte().toULong() + val first = get().toUInt() + var type = (first and 3u).toInt() + + var result: ULong = first.toULong() shr 2 + if (type-- == 0) return result // type 0 + + result = result or (get() shl 6) + if (type-- == 0) return result // type 1 + + result = result or (get() shl 14) + if (type == 0) return result // type 2 + + return result or (Varint.decode(source) shl 22) + } + + fun encodeSigned(value: Long, sink: DataSink) { + val sigBit: ULong + val x: ULong + if (value < 0) { + x = (-value).toULong() + sigBit = 1u + } else { + x = value.toULong() + sigBit = 0u + } + Varint.encode((x shl 1) or sigBit, sink) + } + + fun decodeSigned(source: DataSource): Long { + val x = Varint.decode(source) + val result = (x shr 1).toLong() + return if ((x and 1u).toInt() != 0) -result else result + } + + fun encode(value: ULong): ByteArray { + return ArrayDataSink().also { encode(value, it) }.toByteArray() + } + + fun decode(packed: ByteArray) = decode(packed.toDataSource()) + + fun encodeSigned(value: Long): ByteArray { + return ArrayDataSink().also { encodeSigned(value, it) }.toByteArray() + } + + fun decodeSigned(data: ByteArray): Long { + return decodeSigned(data.toDataSource()) + } +} diff --git a/src/commonMain/kotlin/net.sergeych.bintools/varint.kt b/src/commonMain/kotlin/net.sergeych.bintools/varint.kt new file mode 100644 index 0000000..7869533 --- /dev/null +++ b/src/commonMain/kotlin/net.sergeych.bintools/varint.kt @@ -0,0 +1,82 @@ +@file:OptIn(ExperimentalUnsignedTypes::class) + +package com.icodici.ubdata + +import net.sergeych.bintools.ArrayDataSink +import net.sergeych.bintools.DataSink +import net.sergeych.bintools.DataSource +import net.sergeych.bintools.toDataSource + +/** + * Variable-length long integer encoding. the MSB (0x80) bit of each byte flags + * that it is not the last one, and all ncecssary bits are encoded with 7-bit + * portions, LSB to MSB (big endian of sorts). + * + * There is slower but more compact encoding variant, [Smartint] that is better when + * encoding numbers that needs more than 22 bits. With smaller numbers its either + * same or even worse, see [Smartint] docs. + */ +object Varint { + fun encodeSigned(value: Long, sink: DataSink): Unit { + var sigBit: ULong + var x: ULong + if (value < 0) { + x = (-value).toULong() + sigBit = 1u + } else { + x = value.toULong() + sigBit = 0u + } + encode((x shl 1) or sigBit, sink) + } + + fun encode(value: ULong, dout: DataSink) { + var rest = value + do { + val x = (rest and 127u).toInt() + rest = rest shr 7 + if (rest > 0u) + dout.writeByte(x or 0x80) + else + dout.writeByte(x) + + } while (rest > 0u) + } + + fun decode(source: DataSource): ULong { + var result: ULong = 0u + var count = 0 + while (true) { + val x = source.readUByte().toInt() + result = result or ((x and 0x7F).toULong() shl count) + if ((x and 0x80) == 0) + break + count += 7 + } + return result + } + + + fun decodeSigned(source: DataSource): Long { + val x = decode(source) + val result = (x shr 1).toLong() + return if ((x and 1u).toInt() != 0) -result else result + } + + fun encode(value: ULong): ByteArray { + return ArrayDataSink().also { encode(value, it) }.toByteArray() + } + + fun decode(packed: ByteArray) = decode(packed.toDataSource()) + + fun encodeSigned(value: Long): ByteArray { + return ArrayDataSink().also { encodeSigned(value, it) }.toByteArray() + } + + fun decodeSigned(data: ByteArray): Long { + return decodeSigned(data.toDataSource()) + } + + + +} diff --git a/src/commonTest/kotlin/bintools/SmartintTest.kt b/src/commonTest/kotlin/bintools/SmartintTest.kt new file mode 100644 index 0000000..802faa6 --- /dev/null +++ b/src/commonTest/kotlin/bintools/SmartintTest.kt @@ -0,0 +1,44 @@ +package bintools + +import com.icodici.ubdata.Smartint +import net.sergeych.bintools.encodeToHex +import kotlin.test.Test +import kotlin.test.assertEquals + +class SmartintTest { + + fun testValue(x: Long) { + assertEquals(x.toULong(), Smartint.decode(Smartint.encode(x.toULong()))) + assertEquals(x, Smartint.decodeSigned(Smartint.encodeSigned(x))) + println("+ ${x}: ${Smartint.encode(x.toULong()).encodeToHex()}") + } + + fun testAround(bits: Int) { + println("----- $bits -----") + val window = 5 + var median: Long = (1.toULong() shl bits).toLong() + for( x in (median-2)..(median+2)) { + testValue(x) + } + median = median * 3 / 2 + for( x in (median-5)..(median+5)) { + testValue(x) + } + } + + @Test + fun encode() { + for( i in 0..70) testValue(i.toLong()) + testAround(6) + testAround(14) + testAround(22) + testAround(29) + testAround(36) + testValue(-1) +// testAround(28) + } + + @Test + fun decode() { + } +} \ No newline at end of file diff --git a/src/commonTest/kotlin/bintools/VarintTest.kt b/src/commonTest/kotlin/bintools/VarintTest.kt new file mode 100644 index 0000000..8a7de1d --- /dev/null +++ b/src/commonTest/kotlin/bintools/VarintTest.kt @@ -0,0 +1,40 @@ +package bintools + +import com.icodici.ubdata.Varint +import net.sergeych.bintools.encodeToHex +import kotlin.test.Test +import kotlin.test.assertEquals + +class VarintTest { + + fun testValue(x: Long) { + assertEquals(x.toULong(), Varint.decode(Varint.encode(x.toULong()))) + assertEquals(x, Varint.decodeSigned(Varint.encodeSigned(x))) + println("+ ${x}: ${Varint.encode(x.toULong()).encodeToHex()}") + } + + fun testAround(bits: Int) { + val window = 5 + var median: Long = (1.toULong() shl bits).toLong() + for( x in (median-5)..(median+5)) { + testValue(x) + } + median = median * 3 / 2 + for( x in (median-5)..(median+5)) { + testValue(x) + } + } + + @Test + fun encode() { +// for( i in 0..300) testValue(i.toLong()) + testAround(7) + testAround(14) + testAround(21) + testAround(28) + } + + @Test + fun decode() { + } +} \ No newline at end of file