allow reading specific parts of an NBT structure as raw data to preve…

…nt excessive memory usage from large numbers of small child tags
aternosorg · May 10, 2022 · 859f4a6 · 859f4a6
1 parent 3cb087c
commit 859f4a6
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Showing 17 changed files with 454 additions and 15 deletions.
diff --git a/src/Tag/ArrayValueTag.php b/src/Tag/ArrayValueTag.php
@@ -5,6 +5,7 @@
 use ArrayAccess;
 use Aternos\Nbt\IO\Reader\Reader;
 use Aternos\Nbt\IO\Writer\Writer;
+use BadMethodCallException;
 use Countable;
 use Exception;
 use Iterator;
@@ -28,13 +29,26 @@ public function writeContent(Writer $writer): static
         return $this;
     }
 
+    /**
+     * @inheritDoc
+     */
     protected function readContent(Reader $reader): static
     {
         $length = $reader->getDeserializer()->readLengthPrefix()->getValue();
         $this->valueArray = $this->readValues($reader, $length);
         return $this;
     }
 
+    /**
+     * @inheritDoc
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        $length = $reader->getDeserializer()->readLengthPrefix();
+        $valueData = static::readValuesRaw($reader, $length->getValue());
+        return $length->getRawData() . $valueData;
+    }
+
     /**
      * @param Writer $writer
      * @return string
@@ -48,6 +62,16 @@ abstract protected function writeValues(Writer $writer): string;
      */
     abstract protected function readValues(Reader $reader, int $length): array;
 
+    /**
+     * @param Reader $reader
+     * @param int $length
+     * @return string
+     */
+    protected static function readValuesRaw(Reader $reader, int $length): string
+    {
+        throw new BadMethodCallException("Not implemented");
+    }
+
     /**
      * @param $value
      * @return bool

diff --git a/src/Tag/ByteArrayTag.php b/src/Tag/ByteArrayTag.php
@@ -34,6 +34,18 @@ protected function readValues(Reader $reader, int $length): array
         return $values;
     }
 
+    /**
+     * @inheritDoc
+     */
+    protected static function readValuesRaw(Reader $reader, int $length): string
+    {
+        $result = "";
+        for ($i = 0; $i < $length; $i++) {
+            $result .= $reader->getDeserializer()->readByte()->getRawData();
+        }
+        return $result;
+    }
+
     /**
      * @inheritDoc
      */

diff --git a/src/Tag/ByteTag.php b/src/Tag/ByteTag.php
@@ -26,4 +26,12 @@ protected function readContent(Reader $reader): static
         $this->value = $reader->getDeserializer()->readByte()->getValue();
         return $this;
     }
+
+    /**
+     * @inheritDoc
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        return $reader->getDeserializer()->readByte()->getRawData();
+    }
 }
diff --git a/src/Tag/CompoundTag.php b/src/Tag/CompoundTag.php
@@ -17,21 +17,39 @@ class CompoundTag extends Tag implements Iterator, ArrayAccess, Countable
      * @var Tag[]
      */
     protected array $valueArray = [];
+    protected ?string $rawContent = null;
+    protected ?int $rawContentFormat = null;
+
+    /**
+     * @return bool
+     */
+    public function isRaw(): bool
+    {
+        return $this->rawContent !== null;
+    }
 
     /**
      * @inheritDoc
      * @throws Exception
      */
     public function writeContent(Writer $writer): static
     {
+        if($this->isRaw()) {
+            if($this->rawContentFormat !== $writer->getFormat()) {
+                throw new Exception("Cannot change format of raw compound tag");
+            }
+            $writer->write($this->rawContent);
+            return $this;
+        }
+
         $writtenNames = [];
         foreach ($this->valueArray as $value) {
             if (in_array($value->getName(), $writtenNames)) {
                 throw new Exception("Duplicate key '" . $value->getName() . "' in compound tag");
             }
             $value->writeData($writer, true);
         }
-        (new EndTag())->writeData($writer);
+        (new EndTag($this->options))->writeData($writer);
         return $this;
     }
 
@@ -41,12 +59,31 @@ public function writeContent(Writer $writer): static
      */
     protected function readContent(Reader $reader): static
     {
-        while (!(($tag = Tag::load($reader)) instanceof EndTag)) {
-            $this->valueArray[] = $tag;
+        if($this->options->shouldBeReadRaw($this)) {
+            $this->rawContentFormat = $reader->getFormat();
+            $this->rawContent = static::readContentRaw($reader, $this->options);
+            return $this;
+        }
+        while (!(($tag = Tag::load($reader, $this->options, $this)) instanceof EndTag)) {
+            $this->valueArray[] = $tag->setParentTag($this);
         }
         return $this;
     }
 
+    /**
+     * @inheritDoc
+     * @throws Exception
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        $result = "";
+        do {
+            $tag = Tag::loadRaw($reader, $options);
+            $result .= $tag->getData();
+        } while ($tag->getTagType() !== TagType::TAG_End);
+        return $result;
+    }
+
     /**
      * @param Tag $value
      * @inheritDoc
@@ -60,6 +97,9 @@ public function offsetSet($offset, $value): void
         if (!is_string($offset) && !is_null($offset)) {
             throw new Exception("Invalid CompoundTag key");
         }
+        if($this->isRaw()) {
+            throw new Exception("Raw compound tags cannot be modified");
+        }
         if (is_null($offset) && is_null($value->getName())) {
             throw new Exception("Tags inside a CompoundTag must be named.");
         }
@@ -68,6 +108,7 @@ public function offsetSet($offset, $value): void
         } else {
             $offset = $value->getName();
         }
+        $value->setParentTag($this);
         $this->offsetUnset($offset);
         $this->valueArray[] = $value;
     }
@@ -140,11 +181,16 @@ public function offsetGet($offset)
 
     /**
      * @inheritDoc
+     * @throws Exception
      */
     public function offsetUnset($offset)
     {
+        if($this->isRaw()) {
+            throw new Exception("Raw compound tags cannot be modified");
+        }
         foreach ($this->valueArray as $i => $val) {
             if ($val->getName() === $offset) {
+                $val->setParentTag(null);
                 unset($this->valueArray[$i]);
                 break;
             }
@@ -164,6 +210,9 @@ public function count(): int
      */
     protected function getValueString(): string
     {
+        if($this->isRaw()) {
+            return strlen($this->rawContent) . " bytes";
+        }
         return $this->count() . " entr" . ($this->count() === 1 ? "y" : "ies") . "\n{\n" .
             $this->indent(implode(", \n", array_map("strval", array_values($this->valueArray)))) .
             "\n}";
@@ -199,6 +248,7 @@ public function set(?string $name, Tag $tag): CompoundTag
     /**
      * @param string $name
      * @return $this
+     * @throws Exception
      */
     public function delete(string $name): CompoundTag
     {

diff --git a/src/Tag/DoubleTag.php b/src/Tag/DoubleTag.php
@@ -35,6 +35,14 @@ protected function readContent(Reader $reader): static
         return $this;
     }
 
+    /**
+     * @inheritDoc
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        return $reader->getDeserializer()->readDouble()->getRawData();
+    }
+
     /**
      * @inheritDoc
      */

diff --git a/src/Tag/EndTag.php b/src/Tag/EndTag.php
@@ -3,7 +3,6 @@
 namespace Aternos\Nbt\Tag;
 
 use Aternos\Nbt\IO\Reader\Reader;
-use Aternos\Nbt\Deserializer\NbtDeserializer;
 use Aternos\Nbt\IO\Writer\Writer;
 
 class EndTag extends Tag
@@ -29,7 +28,15 @@ protected function readContent(Reader $reader): static
     /**
      * @inheritDoc
      */
-    public function canBeNamed(): bool
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        return "";
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public static function canBeNamed(): bool
     {
         return false;
     }

diff --git a/src/Tag/FloatTag.php b/src/Tag/FloatTag.php
@@ -35,6 +35,14 @@ protected function readContent(Reader $reader): static
         return $this;
     }
 
+    /**
+     * @inheritDoc
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        return $reader->getDeserializer()->readFloat()->getRawData();
+    }
+
     /**
      * @inheritDoc
      */

diff --git a/src/Tag/IntArrayTag.php b/src/Tag/IntArrayTag.php
@@ -32,6 +32,18 @@ protected function readValues(Reader $reader, int $length): array
         return $values;
     }
 
+    /**
+     * @inheritDoc
+     */
+    protected static function readValuesRaw(Reader $reader, int $length): string
+    {
+        $result = "";
+        for ($i = 0; $i < $length; $i++) {
+            $result .= $reader->getDeserializer()->readInt()->getRawData();
+        }
+        return $result;
+    }
+
     /**
      * @inheritDoc
      */

diff --git a/src/Tag/IntTag.php b/src/Tag/IntTag.php
@@ -26,4 +26,12 @@ protected function readContent(Reader $reader): static
         $this->value = $reader->getDeserializer()->readInt()->getValue();
         return $this;
     }
+
+    /**
+     * @inheritDoc
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        return $reader->getDeserializer()->readInt()->getRawData();
+    }
 }
diff --git a/src/Tag/ListTag.php b/src/Tag/ListTag.php
@@ -71,7 +71,7 @@ protected function readValues(Reader $reader, int $length): array
             throw new Exception("Unknown ListTag content type " . $this->contentTagType);
         }
         for ($i = 0; $i < $length; $i++) {
-            $values[] = (new $tagClass())->read($reader, false);
+            $values[] = (new $tagClass($this->options))->setParentTag($this)->read($reader, false);
         }
         return $values;
     }
@@ -91,12 +91,38 @@ protected function checkArrayValue($value): bool
         return $value::TYPE === $this->contentTagType;
     }
 
+    /**
+     * @inheritDoc
+     */
     protected function readContent(Reader $reader): static
     {
         $this->contentTagType = $reader->getDeserializer()->readByte()->getValue();
         return parent::readContent($reader);
     }
 
+    /**
+     * @inheritDoc
+     * @throws Exception
+     */
+    protected static function readContentRaw(Reader $reader, TagOptions $options): string
+    {
+        $contentTagType = $reader->getDeserializer()->readByte();
+        $length = $reader->getDeserializer()->readLengthPrefix();
+        $valueData = "";
+
+        /** @var Tag $tagClass */
+        $tagClass = Tag::getTagClass($contentTagType->getValue());
+        if (is_null($tagClass)) {
+            throw new Exception("Unknown ListTag content type " . $contentTagType->getValue());
+        }
+        $lengthVal = $length->getValue();
+        for ($i = 0; $i < $lengthVal; $i++) {
+            $valueData .= $tagClass::readRaw($reader, $options, false);
+        }
+
+        return $contentTagType->getRawData() . $length->getRawData() . $valueData;
+    }
+
     /**
      * @inheritDoc
      */
@@ -113,6 +139,29 @@ protected function getTagTypeString(): string
         return parent::getTagTypeString() . "<" . TagType::NAMES[$this->contentTagType] . ">";
     }
 
+    /**
+     * @inheritDoc
+     */
+    public function offsetSet($offset, $value)
+    {
+        /** @var Tag $previousValue */
+        $previousValue = $this->valueArray[$offset] ?? null;
+        parent::offsetSet($offset, $value);
+        $value->setParentTag($this);
+        $previousValue?->setParentTag(null);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    public function offsetUnset($offset)
+    {
+        /** @var Tag $previousValue */
+        $previousValue = $this->valueArray[$offset] ?? null;
+        $previousValue?->setParentTag(null);
+        parent::offsetUnset($offset);
+    }
+
     /**
      * @inheritDoc
      */

diff --git a/src/Tag/LongArrayTag.php b/src/Tag/LongArrayTag.php
@@ -43,6 +43,18 @@ protected function readValues(Reader $reader, int $length): array
         return $values;
     }
 
+    /**
+     * @inheritDoc
+     */
+    protected static function readValuesRaw(Reader $reader, int $length): string
+    {
+        $raw = "";
+        for ($i = 0; $i < $length; $i++) {
+            $raw = $reader->getDeserializer()->readLong()->getRawData();
+        }
+        return $raw;
+    }
+
     /**
      * @inheritDoc
      */