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load-service: various refactoring, updating comments etc
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@davmac314
davmac314 committed Nov 30, 2024
1 parent c9870a7 commit 47558c2
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Showing 3 changed files with 101 additions and 64 deletions.
141 changes: 88 additions & 53 deletions src/includes/load-service.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1104,10 +1104,16 @@ void process_service_file(string name, file_input_stack &service_input, T proces
inline void dummy_lint(const char *) {}

// Resolve variables from an environment
inline const char *resolve_env_var(const string &name, const environment::env_map &envmap){
inline const char *resolve_env_var(const string &name, const environment::env_map &envmap)
{
return envmap.lookup(name);
};

inline const char *null_resolve_env_var(const string &name)
{
return nullptr;
}

// Substitute variable references in a value with their values. Specified offsets must give
// the location of separate arguments after word splitting and are adjusted appropriately.
// If you simply wish to substitute all variables in the given string, pass an offsets list
Expand All @@ -1118,8 +1124,7 @@ inline const char *resolve_env_var(const string &name, const environment::env_ma
// std::bad_alloc on allocation failure
template <typename T>
static void value_var_subst(const char *setting_name, std::string &line,
std::list<std::pair<unsigned,unsigned>> &offsets, T &var_resolve,
environment::env_map const *envmap, const char *argval)
std::list<std::pair<unsigned,unsigned>> &offsets, const T &var_resolve, const char *argval)
{
auto dindx = line.find('$');
if (dindx == string::npos) {
Expand Down Expand Up @@ -1200,7 +1205,7 @@ static void value_var_subst(const char *setting_name, std::string &line,
}
size_t line_len_before = r_line.size();
string_view resolved_vw;
auto *resolved = is_arg ? argval : (envmap ? var_resolve(name, *envmap) : nullptr);
auto *resolved = is_arg ? argval : var_resolve(name);
if (resolved) {
resolved_vw = resolved;
}
Expand Down Expand Up @@ -1324,7 +1329,7 @@ inline string read_value_with_arg(const char *setting_name, file_pos_ref input_p

std::list<std::pair<unsigned,unsigned>> offsets;
offsets.emplace_back(0, rval.size());
value_var_subst(setting_name, rval, offsets, resolve_env_var, nullptr, argval);
value_var_subst(setting_name, rval, offsets, null_resolve_env_var, argval);
return rval;
}

Expand All @@ -1342,7 +1347,7 @@ inline string read_include_path(string const &svcname, string const &meta_cmd, f

std::list<std::pair<unsigned,unsigned>> offsets;
offsets.emplace_back(0, rval.size());
value_var_subst(meta_cmd.c_str(), rval, offsets, resolve_env_var, nullptr, argval);
value_var_subst(meta_cmd.c_str(), rval, offsets, null_resolve_env_var, argval);
return rval;
}

Expand Down Expand Up @@ -1432,23 +1437,30 @@ class service_settings_wrapper
char inittab_line[sizeof(utmpx().ut_line)] = {0};
#endif

// Finalise settings (after processing all setting lines), perform some basic sanity checks and
// optionally some additional lint checks. May throw service_description_exc
//
// Note: we have the do_report_lint parameter to prevent code (and strings) being emitted for lint
// checks even when the dummy_lint function is used. (Ideally the compiler would optimise them away).
// Finalise settings (after processing all setting lines), perform some basic sanity checks
// and optionally some additional lint checks.
//
// Template parameters:
// propagate_sde - whether to propagate service description errors (if false they are reported via report_err)
// (remaining template parameters should be inferred)
// propagate_sde - whether to propagate service description errors (if false, they are
// reported via report_err)
// (remaining template parameters should be inferred)
// Parameters:
// report_error - functor to report any errors
// envmap - environment variables
// report_line - functor to report lint (default: don't report)
// var_subst - functor to resolve environment variable values
template <bool propagate_sde = false, typename T, typename U = decltype(dummy_lint), typename V = decltype(resolve_env_var),
// report_error - functor to report any errors
// service_arg - service argument, if any (may be null)
// envmap - environment variables
// report_line - functor to report lint (default: don't report)
// var_subst - functor to resolve environment variable values
// Throws:
// service_description_exc, bad_alloc
//
// Note: we have the do_report_lint parameter to prevent code (and strings) being emitted for
// lint checks even when the dummy_lint function is used. (Ideally the compiler would optimise
// them away).
//
template <bool propagate_sde = false, typename T, typename U, typename V,
bool do_report_lint = !std::is_same<U, decltype(dummy_lint)>::value>
void finalise(T &report_error, environment::env_map const &envmap, const char *argval, U &report_lint = dummy_lint, V &var_subst = resolve_env_var)
void finalise(T &report_error, const char *service_arg, const U &report_lint,
const V &var_subst)
{
if (service_type == service_type_t::PROCESS || service_type == service_type_t::BGPROCESS
|| service_type == service_type_t::SCRIPTED) {
Expand Down Expand Up @@ -1555,7 +1567,7 @@ class service_settings_wrapper
try {
list<pair<unsigned,unsigned>> str_offsets;
str_offsets.emplace_back(0, setting_value.size());
value_var_subst(setting_name, setting_value, str_offsets, var_subst, &envmap, argval);
value_var_subst(setting_name, setting_value, str_offsets, var_subst, service_arg);
}
catch (service_description_exc &exc) {
if (propagate_sde) throw;
Expand Down Expand Up @@ -1600,40 +1612,63 @@ class service_settings_wrapper
}
}
}

// Finalise settings (after processing all setting lines), perform some basic sanity checks
// and optionally some additional lint checks. Resolve variables from provided env_map.
// See finalise() above.
//
// Throws:
// service_description_exc
//
template <bool propagate_sde = false, typename T, typename U = decltype(dummy_lint),
typename V = decltype(resolve_env_var),
bool do_report_lint = !std::is_same<U, decltype(dummy_lint)>::value>
void finalise(T &report_error, environment::env_map const &envmap, const char *argval,
U &report_lint = dummy_lint, V &var_subst = resolve_env_var)
{
auto do_var_subst = [&](const std::string &name) {
return var_subst(name, envmap);
};
finalise<propagate_sde, T, U, decltype(do_var_subst), do_report_lint>(report_error,
argval, report_lint, do_var_subst);
}
};

// Process a service description line. In general, parse the setting value and record the parsed value
// in a service settings wrapper object. Errors will be reported via service_description_exc exception.
// Process a service description line. In general, parse the setting value and record the parsed
// value in a service settings wrapper object. Errors will be reported via service_description_exc
// exception.
//
// type parameters:
// settings_wrapper : wrapper for service settings
// load_service_t : type of load service function/lambda (see below)
// process_dep_dir_t : type of process_dep_dir function/lambda (see below)
// Type parameters:
// settings_wrapper : wrapper for service settings
// load_service_t : type of load service function/lambda (see below)
// process_dep_dir_t : type of process_dep_dir function/lambda (see below)
//
// parameters:
// settings : wrapper object for service settings
// name : name of the service being processed
// line : the current line of the service description file
// input_pos : the current input position (for error reporting)
// setting : the name of the setting (from the beginning of line)
// setting_op : the operator specified after the setting name
// i : iterator at beginning of setting value (including whitespace)
// end : iterator at end of line
// load_service : function to load a service
// arguments: const char *service_name
// return: a value that can be used (with a dependency type) to construct a
// dependency in the 'depends' vector within the 'settings' object
// process_dep_dir : function to process a dependency directory
// arguments: decltype(settings.depends) &dependencies
// const string &waitsford - directory as specified in parameter
// dependency_type dep_type - type of dependency to add
// throws: service_description_exc, std::bad_alloc, std::length_error (string too long; unlikely)
// Parameters:
// settings : wrapper object for service settings
// name : name of the service being processed
// service_arg : service argument, if any (may be null)
// line : the current line of the service description file
// input_pos : the current input position (for error reporting)
// setting : the name of the setting (from the beginning of line)
// setting_op : the operator specified after the setting name
// i : iterator at beginning of setting value (including whitespace)
// end : iterator at end of line
// load_service : function to load a service
// arguments: const char *service_name
// return: a value that can be used (with a dependency type) to construct a
// dependency in the 'depends' vector within the 'settings' object
// process_dep_dir : function to process a dependency directory
// arguments: decltype(settings.depends) &dependencies
// const string &waitsford - directory as specified in parameter
// dependency_type dep_type - type of dependency to add
// Throws:
// service_description_exc, std::bad_alloc, std::length_error (string too long; unlikely)
template <typename settings_wrapper,
typename load_service_t,
typename process_dep_dir_t>
void process_service_line(settings_wrapper &settings, const char *name, const char *arg, string &line,
file_pos_ref input_pos, string &setting, setting_op_t setting_op, string::iterator &i,
string::iterator &end, load_service_t load_service,
void process_service_line(settings_wrapper &settings, const char *name, const char *service_arg,
string &line, file_pos_ref input_pos, string &setting, setting_op_t setting_op,
string::iterator &i, string::iterator &end, load_service_t load_service,
process_dep_dir_t process_dep_dir)
{
// find the setting:
Expand All @@ -1657,7 +1692,7 @@ void process_service_line(settings_wrapper &settings, const char *name, const ch
settings.working_dir = read_setting_value(input_pos, i, end, nullptr);
break;
case setting_id_t::ENV_FILE:
settings.env_file = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
settings.env_file = read_value_with_arg(setting.c_str(), input_pos, i, end, service_arg);
break;
#if SUPPORT_CGROUPS
case setting_id_t::RUN_IN_CGROUP:
Expand Down Expand Up @@ -1778,21 +1813,21 @@ void process_service_line(settings_wrapper &settings, const char *name, const ch
break;
case setting_id_t::DEPENDS_ON:
{
string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, service_arg);
settings.depends.emplace_back(load_service(dependency_name.c_str()),
dependency_type::REGULAR);
break;
}
case setting_id_t::DEPENDS_MS:
{
string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, service_arg);
settings.depends.emplace_back(load_service(dependency_name.c_str()),
dependency_type::MILESTONE);
break;
}
case setting_id_t::WAITS_FOR:
{
string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
string dependency_name = read_value_with_arg(setting.c_str(), input_pos, i, end, service_arg);
settings.depends.emplace_back(load_service(dependency_name.c_str()),
dependency_type::WAITS_FOR);
break;
Expand All @@ -1817,13 +1852,13 @@ void process_service_line(settings_wrapper &settings, const char *name, const ch
}
case setting_id_t::AFTER:
{
string after_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
string after_name = read_value_with_arg(setting.c_str(), input_pos, i, end, service_arg);
settings.after_svcs.emplace_back(std::move(after_name));
break;
}
case setting_id_t::BEFORE:
{
string before_name = read_value_with_arg(setting.c_str(), input_pos, i, end, arg);
string before_name = read_value_with_arg(setting.c_str(), input_pos, i, end, service_arg);
settings.before_svcs.emplace_back(std::move(before_name));
break;
}
Expand Down
4 changes: 3 additions & 1 deletion src/load-service.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -35,7 +35,9 @@ static void do_env_subst(const char *setting_name, ha_string &line,
{
using namespace dinit_load;
std::string line_s = std::string(line.c_str(), line.length());
value_var_subst(setting_name, line_s, offsets, resolve_env_var, &envmap, arg);
value_var_subst(setting_name, line_s, offsets, [&](const std::string &name) {
return resolve_env_var(name, envmap);
}, arg);
line = line_s;
}

Expand Down
20 changes: 10 additions & 10 deletions src/tests/loadtests.cc
View file
Original file line number Diff line number Diff line change
Expand Up @@ -61,7 +61,7 @@ void test_env_subst()

void test_env_subst2()
{
auto resolve_env_var = [](const std::string &name, environment::env_map const &) {
auto resolve_env_var = [](const std::string &name) {
if (name == "ONE_VAR") return "a";
if (name == "TWOVAR") return "hellohello";
return "";
Expand All @@ -77,7 +77,7 @@ void test_env_subst2()

dinit_load::read_setting_value(fpr, li, le, &offsets);

dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test xa-a~ y${TWOVAR}hellohello$ONE_VAR");

Expand All @@ -89,7 +89,7 @@ void test_env_subst2()

void test_env_subst3()
{
auto resolve_env_var = [](const std::string &name, environment::env_map const &) {
auto resolve_env_var = [](const std::string &name) {
if (name == "EMPTY") return "";
if (name == "WS") return " ";
if (name == "PADDED") return " p ";
Expand All @@ -104,7 +104,7 @@ void test_env_subst3()
std::string::iterator li = line.begin();
std::string::iterator le = line.end();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

auto check_arg = [&](unsigned idx, const char *val)
{
Expand All @@ -118,7 +118,7 @@ void test_env_subst3()
line = "test $EMPTY foo";
li = line.begin(); le = line.end(); offsets.clear();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test foo");
check_arg(1, "");
Expand All @@ -128,7 +128,7 @@ void test_env_subst3()
line = "test $/EMPTY$/EMPTY$/EMPTY foo";
li = line.begin(); le = line.end(); offsets.clear();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test foo");
check_arg(1, "foo");
Expand All @@ -137,7 +137,7 @@ void test_env_subst3()
line = "test $/EMPTY$EMPTY$/EMPTY foo";
li = line.begin(); le = line.end(); offsets.clear();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test foo");
check_arg(1, "");
Expand All @@ -147,7 +147,7 @@ void test_env_subst3()
line = "test abc$/{EMPTY}def";
li = line.begin(); le = line.end(); offsets.clear();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test abcdef");
check_arg(1, "abcdef");
Expand All @@ -156,7 +156,7 @@ void test_env_subst3()
line = "test abc$/{WS}def";
li = line.begin(); le = line.end(); offsets.clear();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test abc def");
check_arg(1, "abc");
Expand All @@ -166,7 +166,7 @@ void test_env_subst3()
line = "test abc$/{PADDED}def";
li = line.begin(); le = line.end(); offsets.clear();
dinit_load::read_setting_value(fpr, li, le, &offsets);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, &tenvmap, nullptr);
dinit_load::value_var_subst("command", line, offsets, resolve_env_var, nullptr);

assert(line == "test abc p def");
check_arg(1, "abc");
Expand Down

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