Replaced nested loop join with hash join algorithm

UPGRADE.md

@@ -5,6 +5,24 @@ Please follow the instructions for your specific version to ensure a smooth upgr
 
 ---
 
+## Upgrading from 0.7.x to 0.8.x
+
+### 1) Joins 
+
+In order to support joining bigger datasets, we had to move from initial NestedLoop join algorithm into Hash Join algorithm.
+
+- the only supported coin expression is `=` (equals) that can be grouped with `AND` and `OR` operators. 
+- `joinPrefix` is now always required, and by default is set to 'joined_'
+- join will always result all columns from both datasets, columns used in join condition will be prefixed with `joinPrefix`.
+
+Other than that, API stays the same. 
+
+Above changes were introduced in all 3 types of joins: 
+
+- `DataFrame::join()`
+- `DataFrame::joinEach()`
+- `DataFrame::crossJoin()`
+
 ## Upgrading from 0.6.x to 0.7.x
 
 ### 1) DataFrame::appendSafe() method was removed

src/core/etl/src/Flow/ETL/DSL/functions.php

@@ -36,11 +36,7 @@
     Formatter,
     Join\Comparison,
     Join\Comparison\Equal,
-    Join\Comparison\GreaterThan,
-    Join\Comparison\GreaterThanEqual,
     Join\Comparison\Identical,
-    Join\Comparison\LessThan,
-    Join\Comparison\LessThanEqual,
     Join\Expression,
     Loader,
     Partition,
@@ -1163,31 +1159,6 @@ function compare_any(Comparison ...$comparisons) : Comparison\Any
     return new Comparison\Any(...$comparisons);
 }
 
-function greater_than(Reference|string $left, Reference|string $right) : GreaterThan
-{
-    return new GreaterThan($left, $right);
-}
-
-function greater_than_equal(Reference|string $left, Reference|string $right) : GreaterThanEqual
-{
-    return new GreaterThanEqual($left, $right);
-}
-
-function less_than(Reference|string $left, Reference|string $right) : LessThan
-{
-    return new LessThan($left, $right);
-}
-
-function less_than_equal(Reference|string $left, Reference|string $right) : LessThanEqual
-{
-    return new LessThanEqual($left, $right);
-}
-
-function negation(Comparison $comparison) : Comparison\Not
-{
-    return new Comparison\Not($comparison);
-}
-
 function join_on(array|Comparison $comparisons, string $joinPrefix = '') : Expression
 {
     return Expression::on($comparisons, $joinPrefix);

src/core/etl/src/Flow/ETL/DataFrame.php

@@ -17,10 +17,16 @@
 use Flow\ETL\Loader\StreamLoader\Output;
 use Flow\ETL\Partition\ScalarFunctionFilter;
 use Flow\ETL\PHP\Type\{AutoCaster, Caster};
-use Flow\ETL\Pipeline\{BatchingPipeline, CachingPipeline, CollectingPipeline, GroupByPipeline, PartitioningPipeline, VoidPipeline};
+use Flow\ETL\Pipeline\{BatchingPipeline,
+    CachingPipeline,
+    CollectingPipeline,
+    GroupByPipeline,
+    HashJoinPipeline,
+    PartitioningPipeline,
+    VoidPipeline};
 use Flow\ETL\Row\{Reference, References, Schema};
 use Flow\ETL\Transformer\StyleConverter\StringStyles;
-use Flow\ETL\Transformer\{AutoCastTransformer, CallbackRowTransformer, CrossJoinRowsTransformer, DropDuplicatesTransformer, DropPartitionsTransformer, EntryNameStyleConverterTransformer, JoinEachRowsTransformer, JoinRowsTransformer, KeepEntriesTransformer, LimitTransformer, RemoveEntriesTransformer, RenameAllCaseTransformer, RenameEntryTransformer, RenameStrReplaceAllEntriesTransformer, ScalarFunctionFilterTransformer, ScalarFunctionTransformer, UntilTransformer, WindowFunctionTransformer};
+use Flow\ETL\Transformer\{AutoCastTransformer, CallbackRowTransformer, CrossJoinRowsTransformer, DropDuplicatesTransformer, DropPartitionsTransformer, EntryNameStyleConverterTransformer, JoinEachRowsTransformer, KeepEntriesTransformer, LimitTransformer, RemoveEntriesTransformer, RenameAllCaseTransformer, RenameEntryTransformer, RenameStrReplaceAllEntriesTransformer, ScalarFunctionFilterTransformer, ScalarFunctionTransformer, UntilTransformer, WindowFunctionTransformer};
 use Flow\RDSL\AccessControl\{AllowAll, AllowList, DenyAll};
 use Flow\RDSL\Attribute\DSLMethod;
 use Flow\RDSL\{Builder, DSLNamespace, Executor, Finder};
@@ -452,19 +458,11 @@ public function groupBy(string|Reference ...$entries) : GroupedDataFrame
      */
     public function join(self $dataFrame, Expression $on, string|Join $type = Join::left) : self
     {
-        if ($type instanceof Join) {
-            $type = $type->name;
+        if (\is_string($type)) {
+            $type = Join::from($type);
         }
 
-        $transformer = match ($type) {
-            Join::left->value => JoinRowsTransformer::left($dataFrame, $on),
-            Join::left_anti->value => JoinRowsTransformer::leftAnti($dataFrame, $on),
-            Join::right->value => JoinRowsTransformer::right($dataFrame, $on),
-            Join::inner->value => JoinRowsTransformer::inner($dataFrame, $on),
-            default => throw new InvalidArgumentException('Unsupported join type')
-        };
-
-        $this->pipeline->add($transformer);
+        $this->pipeline = new HashJoinPipeline($this->pipeline, $dataFrame, $on, $type);
 
         return $this;
     }

src/core/etl/src/Flow/ETL/Exception/DuplicatedEntriesException.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Exception;
+
+final class DuplicatedEntriesException extends InvalidArgumentException
+{
+}

src/core/etl/src/Flow/ETL/Exception/JoinException.php

@@ -0,0 +1,9 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Exception;
+
+final class JoinException extends RuntimeException
+{
+}

src/core/etl/src/Flow/ETL/Hash/Algorithm.php

@@ -0,0 +1,10 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Hash;
+
+interface Algorithm
+{
+    public function hash(string $value) : string;
+}

src/core/etl/src/Flow/ETL/Hash/NativePHPHash.php

@@ -0,0 +1,20 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Hash;
+
+final class NativePHPHash implements Algorithm
+{
+    public function __construct(private string $algorithm = 'xxh128', private bool $binary = false, private array $options = [])
+    {
+        if (!\in_array($algorithm, \hash_algos(), true)) {
+            throw new \InvalidArgumentException(\sprintf('Hashing algorithm "%s" is not supported', $algorithm));
+        }
+    }
+
+    public function hash(string $value) : string
+    {
+        return \hash($this->algorithm, $value, $this->binary, $this->options);
+    }
+}

src/core/etl/src/Flow/ETL/Hash/PlainText.php

@@ -0,0 +1,13 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Flow\ETL\Hash;
+
+final class PlainText implements Algorithm
+{
+    public function hash(string $value) : string
+    {
+        return $value;
+    }
+}

src/core/etl/src/Flow/ETL/Join/Expression.php

@@ -5,7 +5,7 @@
 namespace Flow\ETL\Join;
 
 use Flow\ETL\Exception\RuntimeException;
-use Flow\ETL\Join\Comparison\{All, Identical};
+use Flow\ETL\Join\Comparison\{All, Equal};
 use Flow\ETL\Row;
 use Flow\ETL\Row\Reference;
 
@@ -20,7 +20,7 @@ public function __construct(
     /**
      * @param array<Comparison>|array<string, string>|Comparison $comparison
      */
-    public static function on(array|Comparison $comparison, string $joinPrefix = '') : self
+    public static function on(array|Comparison $comparison, string $joinPrefix = 'joined_') : self
     {
         if (\is_array($comparison)) {
             /** @var array<Comparison> $comparisons */
@@ -41,7 +41,7 @@ public static function on(array|Comparison $comparison, string $joinPrefix = '')
                     throw new RuntimeException('Expected right entry name to be string, got ' . \gettype($right) . ". Example: ['id' => 'id']");
                 }
 
-                $comparisons[] = new Identical($left, $right);
+                $comparisons[] = new Equal($left, $right);
             }
 
             return new self(new All(...$comparisons), $joinPrefix);

src/core/etl/src/Flow/ETL/Pipeline/BatchingPipeline.php

@@ -20,7 +20,7 @@ final class BatchingPipeline implements OverridingPipeline, Pipeline
      */
     public function __construct(private readonly Pipeline $pipeline, private readonly int $size)
     {
-        $this->nextPipeline = $pipeline->cleanCopy();
+        $this->nextPipeline = new SynchronousPipeline();
 
         if ($this->size <= 0) {
             throw new InvalidArgumentException('Batch size must be greater than 0, given: ' . $this->size);