From 589bd7a39610b181c286e88c906a50a3872588a7 Mon Sep 17 00:00:00 2001
From: Alexander Momchilov <alexander.momchilov@shopify.com>
Date: Wed, 13 May 2026 10:29:47 -0400
Subject: [PATCH] Reduce stat syscalls

Don't check `File.file?` before `File.read`. If anything it's a [TOC/TOU](https://en.wikipedia.org/wiki/Time-of-check_to_time-of-use) error, but it's also an extra stat system call.

Instead, just try to read, and rescue the exception, if any.
---
 lib/spoom/context/bundle.rb                     |  9 +++++++--
 lib/spoom/context/sorbet.rb                     |  9 +++++++--
 lib/spoom/file_collector.rb                     | 10 ++++++++--
 lib/spoom/sorbet/metrics/metrics_file_parser.rb |  1 +
 4 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/lib/spoom/context/bundle.rb b/lib/spoom/context/bundle.rb
index e7bcafaa..dcee9c2f 100644
--- a/lib/spoom/context/bundle.rb
+++ b/lib/spoom/context/bundle.rb
@@ -10,12 +10,16 @@ module Bundle
       #: -> String?
       def read_gemfile
         read("Gemfile")
+      rescue Errno::ENOENT, Errno::EACCES
+        nil
       end
 
       # Read the contents of the Gemfile.lock in this context directory
       #: -> String?
       def read_gemfile_lock
         read("Gemfile.lock")
+      rescue Errno::ENOENT, Errno::EACCES
+        nil
       end
 
       # Set the `contents` of the Gemfile in this context directory
@@ -45,9 +49,10 @@ def bundle_exec(command, version: nil, capture_err: true)
 
       #: -> Hash[String, Bundler::LazySpecification]
       def gemfile_lock_specs
-        return {} unless file?("Gemfile.lock")
+        lockfile = read_gemfile_lock
+        return {} unless lockfile
 
-        parser = Bundler::LockfileParser.new(read_gemfile_lock)
+        parser = Bundler::LockfileParser.new(lockfile)
         parser.specs.to_h { |spec| [spec.name, spec] }
       end
 
diff --git a/lib/spoom/context/sorbet.rb b/lib/spoom/context/sorbet.rb
index 4069015f..35e46165 100644
--- a/lib/spoom/context/sorbet.rb
+++ b/lib/spoom/context/sorbet.rb
@@ -42,10 +42,15 @@ def srb_metrics(*arg, sorbet_bin: nil, capture_err: true)
           sorbet_bin: sorbet_bin,
           capture_err: capture_err,
         )
-        return unless file?(metrics_file)
 
         metrics_path = absolute_path_to(metrics_file)
-        metrics = Spoom::Sorbet::Metrics::MetricsFileParser.parse_file(metrics_path)
+
+        begin
+          metrics = Spoom::Sorbet::Metrics::MetricsFileParser.parse_file(metrics_path)
+        rescue Errno::ENOENT, Errno::EACCES
+          return
+        end
+
         remove!(metrics_file)
         metrics
       end
diff --git a/lib/spoom/file_collector.rb b/lib/spoom/file_collector.rb
index 2c7b7927..293dda60 100644
--- a/lib/spoom/file_collector.rb
+++ b/lib/spoom/file_collector.rb
@@ -33,9 +33,15 @@ def visit_path(path)
 
       return if excluded_path?(path)
 
-      if File.file?(path)
+      begin
+        stat = File.stat(path)
+      rescue Errno::ENOENT, Errno::EACCES
+        return
+      end
+
+      if stat.file?
         visit_file(path)
-      elsif File.directory?(path)
+      elsif stat.directory?
         visit_directory(path)
       else # rubocop:disable Style/EmptyElse
         # Ignore aliases, sockets, etc.
diff --git a/lib/spoom/sorbet/metrics/metrics_file_parser.rb b/lib/spoom/sorbet/metrics/metrics_file_parser.rb
index 71fbd408..5a2ac1f8 100644
--- a/lib/spoom/sorbet/metrics/metrics_file_parser.rb
+++ b/lib/spoom/sorbet/metrics/metrics_file_parser.rb
@@ -10,6 +10,7 @@ module MetricsFileParser
         DEFAULT_PREFIX = "ruby_typer.unknown."
 
         class << self
+          # Raises if `path` doesn't point to a valid file that we have access to (see `File.read` for details)
           #: (String path, ?String prefix) -> Hash[String, Integer]
           def parse_file(path, prefix = DEFAULT_PREFIX)
             parse_string(File.read(path), prefix)