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Expand WP_Git_Cached_Index to support more operations and commits
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@adamziel
adamziel committed Dec 30, 2024
1 parent fdf9393 commit 63ed39a
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Showing 2 changed files with 269 additions and 24 deletions.
270 changes: 252 additions & 18 deletions packages/playground/data-liberation/src/git/WP_Git_Cached_Index.php
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,16 @@ class WP_Git_Cached_Index {

private $fs;

private $oid;
private $type;
private $length;
private $contents;
private $parsed_commit;
private $parsed_tree;
private $last_error;

private const DELETE_PLACEHOLDER = 'DELETE_PLACEHOLDER';

public function __construct(
WP_Abstract_Filesystem $fs
) {
Expand All @@ -22,45 +32,145 @@ public function __construct(
}

/**
* @TODO: Streaming read
* @TODO: Streaming read. Don't load everything into memory.
*/
public function get_object($oid) {
public function read_object($oid) {
// Reset the object state
$this->oid = null;
$this->type = null;
$this->length = null;
$this->contents = null;
$this->parsed_commit = null;
$this->parsed_tree = null;

$contents = $this->fs->read_file($this->get_object_path($oid));
return WP_Git_Pack_Processor::inflate($contents);
$contents = WP_Git_Pack_Processor::inflate($contents);
$type_length = strpos($contents, ' ');
$this->oid = $oid;
$this->type = substr($contents, 0, $type_length);
$this->length = substr($contents, $type_length + 1, strpos($contents, "\x00", $type_length) - $type_length - 1);
$this->contents = substr($contents, strpos($contents, "\x00", $type_length) + 1);
if($this->type === WP_Git_Pack_Processor::OBJECT_NAMES[WP_Git_Pack_Processor::OBJECT_TYPE_COMMIT]) {
$this->parsed_commit = WP_Git_Pack_Processor::parse_commit_message($this->contents);
} else if($this->type === WP_Git_Pack_Processor::OBJECT_NAMES[WP_Git_Pack_Processor::OBJECT_TYPE_TREE]) {
$this->parsed_tree = WP_Git_Pack_Processor::parse_tree_bytes($this->contents);
}
return true;
}

public function oid_exists($oid) {
return $this->fs->is_file($this->get_object_path($oid));
}

public function set_head($head, $oid) {
if($head !== 'HEAD' && !str_starts_with($head, 'refs/heads/')) {
_doing_it_wrong(__METHOD__, 'Invalid head: ' . $head);
public function read_by_path($path, $root_tree_oid=null) {
if($root_tree_oid === null) {
$head_oid = $this->get_ref_head('HEAD');
if(false === $this->read_object($head_oid)) {
return false;
}
$root_tree_oid = $this->get_commit_tree_oid();
}
if(false === $this->read_object($root_tree_oid)) {
return false;
}
return $this->fs->put_contents($head, $oid);
}

public function get_head($head='HEAD') {
if($head === 'HEAD') {
$head_contents = $this->fs->read_file('HEAD');
if(strpos($head_contents, 'ref: ') !== 0) {
$path = trim($path, '/');
if (empty($path)) {
return true;
}

$path_segments = explode('/', $path);
foreach ($path_segments as $segment) {
if (!isset($this->parsed_tree[$segment])) {
return null;
}
$head = trim(substr($head_contents, 5));
} else if(!str_starts_with($head, 'refs/heads/')) {
_doing_it_wrong(__METHOD__, 'Invalid head: ' . $head);
$next_oid = $this->parsed_tree[$segment]['sha1'];
if(false === $this->read_object($next_oid)) {
return false;
}
}

return true;
}

public function get_descendants($tree_oid) {
if(false === $this->read_object($tree_oid)) {
return [];
}
foreach ($this->parsed_tree as $object) {
if ($object['mode'] === WP_Git_Pack_Processor::FILE_MODE_DIRECTORY) {
yield from $this->get_descendants($object['sha1']);
} else {
yield $object;
}
}
}

public function get_type() {
return $this->type;
}

public function get_length() {
return $this->length;
}

public function get_contents() {
return $this->contents;
}

public function get_parsed_commit() {
return $this->parsed_commit;
}

public function get_commit_tree_oid() {
return $this->parsed_commit['tree'];
}

public function get_parsed_tree() {
return $this->parsed_tree;
}

public function set_ref_head($ref, $oid) {
if($ref !== 'HEAD' && !str_starts_with($ref, 'refs/heads/')) {
_doing_it_wrong(__METHOD__, 'Invalid head: ' . $ref, '1.0.0');
return false;
}
return $this->fs->put_contents($ref, $oid);
}

public function get_ref_head($ref='HEAD') {
if($ref === 'HEAD') {
$ref = $this->get_HEAD_ref();
} else if(!str_starts_with($ref, 'refs/heads/')) {
_doing_it_wrong(__METHOD__, 'Invalid head: ' . $ref, '1.0.0');
return false;
}
return trim($this->fs->read_file($head));
return trim($this->fs->read_file($ref));
}

private function get_HEAD_ref() {
$ref_contents = $this->fs->read_file('HEAD');
if(strpos($ref_contents, 'ref: ') !== 0) {
return null;
}
return trim(substr($ref_contents, 5));
}

public function add_object($type, $content) {
$oid = sha1(self::wrap_git_object($type, $content));
if($this->oid_exists($oid)) {
return $oid;
}
$oid_path = $this->get_object_path($oid);
$oid_dir = dirname($oid_path);
if(!$this->fs->is_dir($oid_dir)) {
$this->fs->mkdir($oid_dir, true);
}
$success = $this->fs->put_contents(
$this->get_object_path($oid),
WP_Git_Pack_Processor::deflate($content)
WP_Git_Pack_Processor::deflate(
self::wrap_git_object($type, $content)
)
);
if(!$success) {
return false;
Expand All @@ -78,4 +188,128 @@ static private function wrap_git_object($type, $object) {
return "$type_name $length\x00" . $object;
}

}
public function commit($changeset, $commit_meta=[]) {
$commit_meta['author'] = $commit_meta['author'] ?? 'John Doe <john@example.com>';
$commit_meta['committer'] = $commit_meta['committer'] ?? 'John Doe <john@example.com>';
$commit_meta['message'] = $commit_meta['message'] ?? 'Changes';

// First process all blob updates
$updates = $changeset['updates'] ?? [];
$deletes = $changeset['deletes'] ?? [];
$move_trees = $changeset['move_trees'] ?? [];

// Track which trees need updating
$changed_trees = [
'/' => ['entries' => []]
];

// Process blob updates
foreach ($updates as $path => $content) {
$blob_oid = $this->add_object(WP_Git_Pack_Processor::OBJECT_TYPE_BLOB, $content);
$this->mark_tree_path_changed($changed_trees, dirname($path));
$changed_trees[dirname($path)]['entries'][basename($path)] = [
'name' => basename($path),
'mode' => WP_Git_Pack_Processor::FILE_MODE_REGULAR_NON_EXECUTABLE,
'sha1' => $blob_oid
];
}

// Process deletes
foreach ($deletes as $path) {
if (!$this->read_by_path(dirname($path))) {
_doing_it_wrong(__METHOD__, 'File not found in HEAD: ' . $path, '1.0.0');
return false;
}
$this->mark_tree_path_changed($changed_trees, dirname($path));
$changed_trees[dirname($path)]['entries'][basename($path)] = self::DELETE_PLACEHOLDER;
}

// Process tree moves
foreach ($move_trees as $old_path => $new_path) {
if (!$this->read_by_path($old_path)) {
_doing_it_wrong(__METHOD__, 'Path not found in HEAD: ' . $old_path, '1.0.0');
return false;
}
$this->mark_tree_path_changed($changed_trees, dirname($old_path));
$this->mark_tree_path_changed($changed_trees, dirname($new_path));

$changed_trees[dirname($old_path)]['entries'][basename($old_path)] = self::DELETE_PLACEHOLDER;
$changed_trees[dirname($new_path)]['entries'][basename($new_path)] = [
'name' => basename($new_path),
'mode' => WP_Git_Pack_Processor::FILE_MODE_DIRECTORY,
'sha1' => $this->oid
];
}

// Process trees bottom-up recursively
$root_tree_oid = $this->commit_tree('/', $changed_trees);

// Create commit object
$commit_message = [];
$commit_message[] = "tree " . $root_tree_oid;
if($this->get_ref_head('HEAD')) {
$commit_message[] = "parent " . $this->get_ref_head('HEAD');
}
$commit_message[] = "author " . $commit_meta['author'];
$commit_message[] = "committer " . $commit_meta['committer'];
$commit_message[] = "\n" . $commit_meta['message'];
$commit_message = implode("\n", $commit_message);
$commit_oid = $this->add_object(WP_Git_Pack_Processor::OBJECT_TYPE_COMMIT, $commit_message);

// Update HEAD
$head_ref = $this->get_HEAD_ref();
if(false === $this->set_ref_head($head_ref, $commit_oid)) {
$this->last_error = 'Failed to set HEAD';
return false;
}
return $commit_oid;
}

private function mark_tree_path_changed(&$changed_trees, $path) {
while ($path !== '/') {
if (!isset($changed_trees[$path])) {
$changed_trees[$path] = ['entries' => []];
}
$path = dirname($path);
}
}

private function commit_tree($path, $changed_trees) {
$tree_objects = [];

// Load existing tree if it exists
if ($this->read_by_path($path)) {
$tree_objects = $this->get_parsed_tree();
}

// Apply any changes to this tree
if (isset($changed_trees[$path]['entries'])) {
foreach ($changed_trees[$path]['entries'] as $name => $entry) {
if ($entry === self::DELETE_PLACEHOLDER) {
unset($tree_objects[$name]);
} else {
$tree_objects[$name] = $entry;
}
}
}

// Recursively process child trees
foreach ($changed_trees as $child_path => $child_tree) {
if (dirname($child_path) === $path && $child_path !== '/') {
$child_oid = $this->commit_tree($child_path, $changed_trees);
$tree_objects[basename($child_path)] = [
'name' => basename($child_path),
'mode' => WP_Git_Pack_Processor::FILE_MODE_DIRECTORY,
'sha1' => $child_oid
];
}
}

// Create new tree object
return $this->add_object(
WP_Git_Pack_Processor::OBJECT_TYPE_TREE,
WP_Git_Pack_Processor::encode_tree_bytes($tree_objects)
);
}

}
23 changes: 17 additions & 6 deletions packages/playground/data-liberation/src/git/WP_Git_Pack_Processor.php
View file
Original file line number Diff line number Diff line change
Expand Up @@ -155,11 +155,6 @@ static public function encode_packet_line(string $payload): string {
return sprintf("%04x", $length) . $payload;
}

static private function encode_flush(): string {
return "0000";
}


static public function decode($pack_bytes) {
$parsed_pack = self::parse_pack_data($pack_bytes);
$objects = $parsed_pack['objects'];
Expand Down Expand Up @@ -269,7 +264,23 @@ static private function applyDelta($base_bytes, $delta_bytes) {
return $result;
}

static private function parse_tree_bytes($treeContent) {
static public function parse_commit_message($commit_message) {
$lines = explode("\n", $commit_message);
$parsed = [];
foreach($lines as $k => $line) {
if(!trim($line)) {
$parsed['message'] = array_slice($lines, $k + 1);
break;
}
$type_len = strpos($line, ' ');
$type = substr($line, 0, $type_len);
$value = substr($line, $type_len + 1);
$parsed[$type] = $value;
}
return $parsed;
}

static public function parse_tree_bytes($treeContent) {
$offset = 0;
$files = [];

Expand Down

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