Integrate Supervisor code review suggestions

scripts/base/frameworks/cluster/nodes/logger.zeek

@@ -30,8 +30,8 @@ function supervisor_rotation_format_func(ri: Log::RotationFmtInfo): Log::Rotatio
 	{
 	local open_str = strftime(Log::default_rotation_date_format, ri$open);
 	local close_str = strftime(Log::default_rotation_date_format, ri$open);
-	local prefix = fmt("%s__%s__%s__", ri$path, open_str, close_str);
-	local rval = Log::RotationPath($file_prefix=prefix);
+	local base = fmt("%s__%s__%s__", ri$path, open_str, close_str);
+	local rval = Log::RotationPath($file_basename=base);
 	return rval;
 	}
 

scripts/base/frameworks/logging/main.zeek

@@ -154,19 +154,19 @@ export {
 		## just-in-time, as the log rotation is about to happen.  If it
 		## cannot be created, an error is emitted and the rotation process
 		## tries to proceed with rotation inside the working directory.  When
-		## setting this field, beware that renaming files across systems will
-		## generally fail.
+		## setting this field, beware that renaming files across file systems
+		## will generally fail.
 		dir: string &default = default_rotation_dir;
 
-		## A prefix to use for the the rotated log.  Log writers may later
+		## A base name to use for the the rotated log.  Log writers may later
 		## append a file extension of their choosing to this user-chosen
-		## prefix (e.g. if using the default ASCII writer and you want
-		## rotated files of the format "foo-<date>.log", then this prefix
+		## base (e.g. if using the default ASCII writer and you want
+		## rotated files of the format "foo-<date>.log", then this basename
 		## can be set to "foo-<date>" and the ".log" is added later (there's
 		## also generally means of customizing the file extension, too,
 		## like the ``ZEEK_LOG_SUFFIX`` environment variable or
 		## writer-dependent configuration options.
-		file_prefix: string;
+		file_basename: string;
 	};
 
 	## A function that one may use to customize log file rotation paths.
@@ -633,12 +633,12 @@ function Log::rotation_format_func(ri: Log::RotationFmtInfo): Log::RotationPath
 	    default_rotation_postprocessors[WRITER_ASCII] == default_ascii_rotation_postprocessor_func)
 		{
 		open_str = strftime(Log::default_rotation_date_format, ri$open);
-		rval = RotationPath($file_prefix=fmt("%s.%s", ri$path, open_str));
+		rval = RotationPath($file_basename=fmt("%s.%s", ri$path, open_str));
 		}
 	else
 		{
 		open_str = strftime("%y-%m-%d_%H.%M.%S", ri$open);
-		rval = RotationPath($file_prefix=fmt("%s-%s", ri$path, open_str));
+		rval = RotationPath($file_basename=fmt("%s-%s", ri$path, open_str));
 		}
 
 	return rval;

scripts/base/frameworks/supervisor/api.zeek

@@ -118,7 +118,9 @@ export {
 	##          a supervised one.
 	global node: function(): NodeConfig;
 
-	## Hooks intercepted stdout stream for all supervisor's child processes.
+	## Hooks into the stdout stream for all supervisor's child processes.
+	## If a hook terminates with `break`, that will suppress output to the
+	## associated stream.
 	##
 	## node: the name of a previously created node via
 	##       :zeek:see:`Supervisor::create` indicating to which
@@ -130,7 +132,9 @@ export {
 	## msg: line-buffered contents from the stdout of a child process.
 	global stdout_hook: hook(node: string, msg: string);
 
-	## Hooks intercepted stderr stream for all supervisor's child processes.
+	## Hooks into the stderr stream for all supervisor's child processes.
+	## If a hook terminates with `break`, that will suppress output to the
+	## associated stream.
 	##
 	## node: the name of a previously created node via
 	##       :zeek:see:`Supervisor::create` indicating to which

src/logging/Manager.cc

@@ -1505,8 +1505,8 @@ std::string Manager::FormatRotationPath(zeek::EnumValPtr writer,
 	{
 	auto ri = zeek::make_intrusive<zeek::RecordVal>(zeek::BifType::Record::Log::RotationFmtInfo);
 	ri->Assign(0, std::move(writer));
-	ri->Assign<zeek::TimeVal>(2, open);
 	ri->Assign<zeek::StringVal>(1, path.size(), path.data());
+	ri->Assign<zeek::TimeVal>(2, open);
 	ri->Assign<zeek::TimeVal>(3, close);
 	ri->Assign(4, zeek::val_mgr->Bool(terminating));
 	ri->Assign<zeek::Val>(5, std::move(postprocessor));

src/logging/writers/ascii/Ascii.cc

@@ -81,11 +81,10 @@ struct LeftoverLog {
 	std::string error;
 
 	/**
-	 * Return the name of the log without file extension (this is
-	 * what's called "path" in other logging framework parlance).
-	 * E.g. the name of "conn.log" is just "conn".
+	 * Return the "path" (logging framework parlance) of the log without the
+	 * file extension. E.g. the "path" of "conn.log" is just "conn".
 	 */
-	std::string Name() const
+	std::string Path() const
 		{ return filename.substr(0, filename.size() - extension.size()); }
 
 	/**
@@ -97,7 +96,6 @@ struct LeftoverLog {
 
 static std::optional<LeftoverLog> parse_shadow_log(const std::string& fname)
 	{
-	char errbuf[512];
 	auto sfname = shadow_file_prefix + fname;
 
 	LeftoverLog rval;
@@ -108,8 +106,8 @@ static std::optional<LeftoverLog> parse_shadow_log(const std::string& fname)
 
 	if ( ! sf_stream )
 		{
-		bro_strerror_r(errno, errbuf, sizeof(errbuf));
-		rval.error = "Failed to open " + rval.shadow_filename + ": " + errbuf;
+		rval.error = fmt("Failed to open %s: %s",
+		                 rval.shadow_filename.data(), strerror(errno));
 		return rval;
 		}
 
@@ -119,6 +117,7 @@ static std::optional<LeftoverLog> parse_shadow_log(const std::string& fname)
 
 	auto sf_content = std::make_unique<char[]>(sf_len);
 	auto bytes_read = fread(sf_content.get(), 1, sf_len, sf_stream);
+	fclose(sf_stream);
 
 	if ( bytes_read != static_cast<size_t>(sf_len) )
 		{
@@ -126,17 +125,14 @@ static std::optional<LeftoverLog> parse_shadow_log(const std::string& fname)
 		return rval;
 		}
 
-	fclose(sf_stream);
 	std::string_view sf_view(sf_content.get(), sf_len);
 	auto sf_lines = tokenize_string(sf_view, '\n');
 
 	if ( sf_lines.size() < 2 )
 		{
-		snprintf(errbuf, sizeof(errbuf),
-		         "Found leftover log, '%s', but the associated shadow file, "
-		         "'%s', required to process it is invalid",
+		rval.error = fmt("Found leftover log, '%s', but the associated shadow "
+		                 " file, '%s', required to process it is invalid",
 		                 rval.filename.data(), rval.shadow_filename.data());
-		rval.error = errbuf;
 		return rval;
 		}
 
@@ -148,8 +144,8 @@ static std::optional<LeftoverLog> parse_shadow_log(const std::string& fname)
 	// Use shadow file's modification time as creation time.
 	if ( stat(rval.shadow_filename.data(), &st) != 0 )
 		{
-		bro_strerror_r(errno, errbuf, sizeof(errbuf));
-		rval.error = "Failed to stat " + rval.shadow_filename + ": " + errbuf;
+		rval.error = fmt("Failed to stat %s: %s",
+		                 rval.shadow_filename.data(), strerror(errno));
 		return rval;
 		}
 
@@ -158,8 +154,8 @@ static std::optional<LeftoverLog> parse_shadow_log(const std::string& fname)
 	// Use log file's modification time for closing time.
 	if ( stat(rval.filename.data(), &st) != 0 )
 		{
-		bro_strerror_r(errno, errbuf, sizeof(errbuf));
-		rval.error = "Failed to stat " + rval.filename + ": " + errbuf;
+		rval.error = fmt("Failed to stat %s: %s",
+		                 rval.filename.data(), strerror(errno));
 		return rval;
 		}
 
@@ -755,21 +751,21 @@ void Ascii::RotateLeftoverLogs()
 			if ( func )
 				ppf = std::move(func);
 			else
-				reporter->Warning("Could no postprocess log '%s' with intended "
+				reporter->Warning("Could not postprocess log '%s' with intended "
 								  "postprocessor function '%s', proceeding "
 								  " with the default function",
 								  ll.filename.data(), ll.post_proc_func.data());
 			}
 
 		auto rotation_path = log_mgr->FormatRotationPath(
-		        writer_val, ll.Name(), ll.open_time, ll.close_time, false, ppf);
+		        writer_val, ll.Path(), ll.open_time, ll.close_time, false, ppf);
 
 		rotation_path += ll.extension;
 
 		auto rot_info = zeek::make_intrusive<zeek::RecordVal>(rot_info_type);
 		rot_info->Assign(0, writer_val);
 		rot_info->Assign<zeek::StringVal>(1, rotation_path);
-		rot_info->Assign<zeek::StringVal>(2, ll.Name());
+		rot_info->Assign<zeek::StringVal>(2, ll.Path());
 		rot_info->Assign<zeek::TimeVal>(3, ll.open_time);
 		rot_info->Assign<zeek::TimeVal>(4, ll.close_time);
 		rot_info->Assign(5, zeek::val_mgr->False());

src/supervisor/Supervisor.cc

@@ -13,6 +13,7 @@
 #include <cstdarg>
 #include <sstream>
 #include <variant>
+#include <utility>
 
 #include "iosource/Manager.h"
 #include "ZeekString.h"
@@ -79,6 +80,13 @@ struct Stem {
 
 	void Reap();
 
+	/**
+	 * This performs fork() to initialize the supervised-node structure.
+	 * There's three possible outcomes:
+	 *   - return value is SupervisedNode: we are the child process
+	 *   - return value is True: we are the parent and fork() succeeded
+	 *   - return value is False: we are the parent and fork() failed
+	 */
 	std::variant<bool, SupervisedNode> Spawn(SupervisorNode* node);
 
 	int AliveNodeCount() const;
@@ -154,6 +162,21 @@ static std::vector<std::string> extract_msgs(std::string* buffer, char delim)
 	return rval;
 	}
 
+static std::pair<int, std::vector<std::string>>
+read_msgs(int fd, std::string* buffer, char delim)
+	{
+	constexpr auto buf_size = 256;
+	char buf[buf_size];
+
+	int bytes_read = read(fd, buf, buf_size);
+
+	if ( bytes_read <= 0 )
+		return {bytes_read, {}};
+
+	buffer->append(buf, bytes_read);
+	return {bytes_read, extract_msgs(buffer, delim)};
+	}
+
 static std::string make_create_message(const Supervisor::NodeConfig& node)
 	{
 	auto json_str = node.ToJSON();
@@ -551,17 +574,11 @@ size_t zeek::detail::LineBufferedPipe::Process()
 	if ( ! pipe )
 		return 0;
 
-	char buf[256];
-
-	int bytes_read = read(pipe->ReadFD(), buf, 256);
+	auto [bytes_read, msgs] = read_msgs(pipe->ReadFD(), &buffer, '\n');
 
 	if ( bytes_read <= 0 )
 		return 0;
 
-	buffer.append(buf, bytes_read);
-
-	auto msgs = extract_msgs(&buffer, '\n');
-
 	for ( const auto& msg : msgs )
 		Emit(msg.data());
 
@@ -570,13 +587,7 @@ size_t zeek::detail::LineBufferedPipe::Process()
 
 size_t Supervisor::ProcessMessages()
 	{
-	char buf[256];
-	int bytes_read = read(stem_pipe->InFD(), buf, 256);
-
-	if ( bytes_read > 0 )
-		msg_buffer.append(buf, bytes_read);
-
-	auto msgs = extract_msgs(&msg_buffer, '\0');
+	auto [bytes_read, msgs] = read_msgs(stem_pipe->InFD(), &msg_buffer, '\0');
 
 	for ( auto& msg : msgs )
 		{
@@ -1061,8 +1072,7 @@ std::optional<SupervisedNode> Stem::Poll()
 		// No messages from supervisor to process, so return early.
 		return {};
 
-	char buf[256];
-	int bytes_read = read(pipe->InFD(), buf, 256);
+	auto [bytes_read, msgs] = read_msgs(pipe->InFD(), &msg_buffer, '\0');
 
 	if ( bytes_read == 0 )
 		{
@@ -1077,9 +1087,6 @@ std::optional<SupervisedNode> Stem::Poll()
 		return {};
 		}
 
-	msg_buffer.append(buf, bytes_read);
-	auto msgs = extract_msgs(&msg_buffer, '\0');
-
 	for ( auto& msg : msgs )
 		{
 		std::vector<std::string> msg_tokens;

testing/btest/scripts/base/frameworks/logging/rotate-custom-fmt-func.zeek

@@ -22,8 +22,8 @@ function my_rotation_format_func(ri: Log::RotationFmtInfo): Log::RotationPath
 	{
 	local open_str = strftime(Log::default_rotation_date_format, ri$open);
 	local close_str = strftime(Log::default_rotation_date_format, ri$open);
-	local prefix =fmt("%s__%s__%s__", ri$path, open_str, close_str);
-	local rval = Log::RotationPath($file_prefix=prefix);
+	local base = fmt("%s__%s__%s__", ri$path, open_str, close_str);
+	local rval = Log::RotationPath($file_basename=base);
 	return rval;
 	}