From d1f62af44e3b5584437fe1f47f1670d17bb7d11d Mon Sep 17 00:00:00 2001
From: Sadeep Madurange <sadeep@asciimx.com>
Date: Sat, 18 Apr 2026 11:24:46 +0800
Subject: Make code more memory safe.

---
 vcx | 88 +++++++++++++++++++++++++++++++--------------------------------------
 1 file changed, 39 insertions(+), 49 deletions(-)

diff --git a/vcx b/vcx
index 481a797..8931ce0 100644
--- a/vcx
+++ b/vcx
@@ -355,27 +355,21 @@ sub run_commit {
 	# Finalize patch bundle
 	my $patch_bundle_hash = "";
 	if ($use_disk_patch || %patches) {
-		use IO::Compress::Gzip qw(gzip $GzipError);
-		my $tar_data;
+		my $bundle_tmp = File::Spec->catfile(TMP_DIR, "bundle.tar.gz");
+		my $tar = Archive::Tar->new;
+		
 		if ($use_disk_patch) {
-			open my $pt_in, '<:raw', $pt_path;
-			$tar_data = do { local $/; <$pt_in> };
-			close $pt_in;
+			$tar->read($pt_path);
 			unlink $pt_path;
-		} else {
-			my $tar = Archive::Tar->new;
-			$tar->add_data($_, $patches{$_}) for keys %patches;
-			$tar_data = $tar->write();
 		}
 		
-		my $final_payload = $tar_data;
-		# 512 byte factor: Only gzip if bundle is large enough to be worth the overhead
-		if (length($tar_data) > 512) {
-			gzip \$tar_data => \$final_payload or die "Gzip failed: $GzipError";
-		}
+		$tar->add_data($_, $patches{$_}) for keys %patches;
 		
-		$patch_bundle_hash = sha1_hex($final_payload);
-		write_file(get_obj_path($patch_bundle_hash), $final_payload);
+		# Write directly to disk with Gzip to avoid loading huge tarballs into RAM
+		$tar->write($bundle_tmp, COMPRESS_GZIP);
+
+		$patch_bundle_hash = hash_file_content($bundle_tmp);
+		rename($bundle_tmp, get_obj_path($patch_bundle_hash));
 	}
 
 	# Revision file
@@ -586,24 +580,28 @@ sub make_bin_patch {
     return length($patch) > 8 ? $patch : undef; 
 }
 
-sub apply_bin_patch {
-	my ($old_data, $patch) = @_;
-	return $old_data unless defined $patch && length($patch) > 8;
-	
+sub apply_bin_patch_file {
+	my ($target_path, $patch_ref) = @_;
+	my $patch = $$patch_ref;
+	return unless length($patch) > 8;
+
 	my $new_size = unpack("Q", substr($patch, 0, 8));
-	my $new_data = "\0" x $new_size;
-	
-	# Start with existing data as base
-	substr($new_data, 0, length($old_data)) = $old_data; 
 	
+	# Open target file for update and resize
+	open my $fh, '+<:raw', $target_path or die $!;
+	truncate($fh, $new_size);
+
 	my $pos = 8;
 	while ($pos < length($patch)) {
 		my ($offset, $len) = unpack("QL", substr($patch, $pos, 12));
 		$pos += 12;
-		substr($new_data, $offset, $len) = substr($patch, $pos, $len);
+		my $data = substr($patch, $pos, $len);
 		$pos += $len;
+
+		seek($fh, $offset, 0);
+		print $fh $data;
 	}
-	return $new_data;
+	close $fh;
 }
 
 # Convert decimal to a padded 7-char hex string
@@ -819,7 +817,7 @@ sub is_revision {
 sub get_file_version {
 	my ($source, $path) = @_;
 
-	# Default to workspace
+	# Handle Workspace
 	if (!defined $source) {
 		return undef unless -e $path;
 		if ((-s $path // 0) > MEM_LIMIT) {
@@ -832,6 +830,7 @@ sub get_file_version {
 		return \$data;
 	}
 
+	# Resolve Revision
 	my $rev_id = (lc($source) eq 'head') ? read_head() : $source;
 	my $rev_file = File::Spec->catfile(REV_DIR, $rev_id);
 	return undef unless -f $rev_file;
@@ -858,7 +857,7 @@ sub get_file_version {
 	my $obj_path = get_obj_path($node->{hash} // '');
 	return undef unless -f $obj_path;
 
-	# Extract and patch 
+	# Extract Base Object to Temp File
 	my ($tfh, $tpath) = tempfile(DIR => TMP_DIR, UNLINK => 1);
 	binmode $tfh, IO_LAYER;
 	
@@ -868,43 +867,33 @@ sub get_file_version {
 	close $ofh;
 	close $tfh;
 
+	# Apply Patch via Streaming Bundle
 	if ($patch_bundle_hash) {
 		my $bundle_path = get_obj_path($patch_bundle_hash);
-		if (-f $bundle_path && -s $bundle_path > 0) { # Ensure bundle exists and isn't empty
-			open my $bfh, '<:raw', $bundle_path;
-			my $raw_bundle = do { local $/; <$bfh> };
-			close $bfh;
-
-			my $tar_data = (substr($raw_bundle, 0, 2) eq "\x1f\x8b") 
-				? Compress::Zlib::uncompress($raw_bundle) 
-				: $raw_bundle;
-
-			if ($tar_data) {
-				my $tar = Archive::Tar->new;
-				$tar->read($tar_data);
-				
-				my $patch_name = "$path.patch";
-				# FIX: Check if the file exists in the tarball before trying to get it
-				if ($tar->contains_file($patch_name)) {
-					my $p_content = $tar->get_content($patch_name);
-					
+		if (-f $bundle_path && -s $bundle_path > 0) {
+			# Use iterator to find the patch without loading the whole tarball into RAM
+			my $next = Archive::Tar->iter($bundle_path, 1);
+			while (my $f = $next->()) {
+				if ($f->name eq "$path.patch") {
+					my $p_content = $f->get_content();
 					my ($pfh, $ppath) = tempfile(DIR => TMP_DIR, UNLINK => 1);
 					binmode $pfh, ":raw";
 					print $pfh $p_content;
 					close $pfh;
 					
+					# Determine if text patch or binary block replacement
 					if ($p_content =~ /^\d+(?:,\d+)?[adc]\d+/) {
 						system("patch -s -f $tpath < $ppath >/dev/null 2>&1");
 					} else {
-						my $old_data = read_file($tpath);
-						my $new_data = apply_bin_patch($old_data, $p_content);
-						write_file($tpath, $new_data);
+						apply_bin_patch_file($tpath, \$p_content);
 					}
+					last;
 				}
 			}
 		}
 	}
 
+	# Final Output decision based on result size
 	if ((-s $tpath // 0) > MEM_LIMIT) {
 		return $tpath; 
 	} else {
@@ -913,3 +902,4 @@ sub get_file_version {
 	}
 }
 
+
-- 
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