From 49b01549dad2dd4d8b51f2507bcd8a15b28e79eb Mon Sep 17 00:00:00 2001
From: Delyan Angelov <delian66@gmail.com>
Date: Fri, 29 Jan 2021 18:01:22 +0200
Subject: [PATCH] v.vcache: improve tracing of vcache usage

---
 vlib/v/vcache/vcache.v | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/vlib/v/vcache/vcache.v b/vlib/v/vcache/vcache.v
index 75038fd192..aa958460a0 100644
--- a/vlib/v/vcache/vcache.v
+++ b/vlib/v/vcache/vcache.v
@@ -39,6 +39,7 @@ pub fn new_cache_manager(opts []string) CacheManager {
 	if vcache_basepath == '' {
 		vcache_basepath = os.join_path(os.vmodules_dir(), 'cache')
 	}
+	dlog(@FN, 'vcache_basepath: $vcache_basepath | opts:\n     $opts')
 	if !os.is_dir(vcache_basepath) {
 		os.mkdir_all(vcache_basepath) or { panic(err) }
 		readme_content := 'This folder contains cached build artifacts from the V build system.
@@ -61,6 +62,7 @@ pub fn new_cache_manager(opts []string) CacheManager {
 // without affecting the .original_vopts
 pub fn (mut cm CacheManager) set_temporary_options(new_opts []string) {
 	cm.vopts = cm.original_vopts + '#' + new_opts.join('|')
+	dlog(@FN, 'cm.vopts:\n     $cm.vopts')
 }
 
 pub fn (mut cm CacheManager) key2cpath(key string) string {
@@ -77,8 +79,13 @@ pub fn (mut cm CacheManager) key2cpath(key string) string {
 			os.mkdir_all(cprefix_folder) or { panic(err) }
 			os.chmod(cprefix_folder, 0o777)
 		}
+		dlog(@FN, 'new hk')
+		dlog(@FN, '       key: $key')
+		dlog(@FN, '     cpath: $cpath')
+		dlog(@FN, '  cm.vopts:\n     $cm.vopts')
 		cm.k2cpath[key] = cpath
 	}
+	dlog(@FN, 'key: ${key:-30} => cpath: $cpath')
 	return cpath
 }
 
@@ -88,6 +95,7 @@ pub fn (mut cm CacheManager) postfix_with_key2cpath(postfix string, key string)
 
 pub fn (mut cm CacheManager) exists(postfix string, key string) ?string {
 	fpath := cm.postfix_with_key2cpath(postfix, key)
+	dlog(@FN, 'postfix: $postfix | key: $key | fpath: $fpath')
 	if !os.exists(fpath) {
 		return error('does not exist yet')
 	}
@@ -97,11 +105,25 @@ pub fn (mut cm CacheManager) exists(postfix string, key string) ?string {
 pub fn (mut cm CacheManager) save(postfix string, key string, content string) ?string {
 	fpath := cm.postfix_with_key2cpath(postfix, key)
 	os.write_file(fpath, content) ?
+	dlog(@FN, 'postfix: $postfix | key: $key | fpath: $fpath')
 	return fpath
 }
 
 pub fn (mut cm CacheManager) load(postfix string, key string) ?string {
 	fpath := cm.exists(postfix, key) ?
 	content := os.read_file(fpath) ?
+	dlog(@FN, 'postfix: $postfix | key: $key | fpath: $fpath')
 	return content
 }
+
+const process_pid = os.getpid()
+
+pub fn dlog(fname string, s string) {
+	$if trace_use_cache ? {
+		if fname[0] != `|` {
+			eprintln('> VCache | pid: $vcache.process_pid | CacheManager.$fname $s')
+		} else {
+			eprintln('> VCache | pid: $vcache.process_pid $fname $s')
+		}
+	}
+}