Adds HRW state variables, 16 flags and 4 int8s

doc/admin-guide/plugins/header_rewrite.en.rst

@@ -140,6 +140,15 @@ with the word ``else``. The following example illustrates this::
 The ``else`` clause is not a condition, and does not take any flags, it is
 of course optional, but when specified must be followed by at least one operator.
 
+State variables
+---------------
+
+A set of state variables are also available for both conditions and operators.
+There are currently 16 flag states, and 4 8-bit integer states. These states are
+all transactional, meaning they are usable and persistent across all hooks.
+
+The flag states are numbers 0-15, and the integer states are numbers 0-3.
+
 Conditions
 ----------
 
@@ -457,9 +466,10 @@ As a special matcher, the inbound IP addresses can be matched against a list of
 
    cond %{INBOUND:REMOTE-ADDR} {192.168.201.0/24,10.0.0.0/8}
 
-Note that this will not work against the non-IP based conditions, such as the protocol families,
-and the configuration parser will error out. The format here is very specific, in particular no
-white spaces are allowed between the ranges.
+.. note::
+    This will not work against the non-IP based conditions, such as the protocol families,
+    and the configuration parser will error out. The format here is very specific, in particular no
+    white spaces are allowed between the ranges.
 
 IP
 ~~
@@ -569,6 +579,36 @@ RANDOM
 
 Generates a random integer from ``0`` up to (but not including) ``<n>``. Mathematically, ``[0,n)`` or ``0 <= r < n``.
 
+STATE-FLAG
+~~~~~~~~~~
+::
+
+      cond %{STATE-FLAG:<n>}
+
+This condition allows you to check the state of a flag. The ``<n>`` is the
+number of the flag, from 0 to 15. This condition returns a ``true`` or
+``false`` value, depending on the state of the flag.
+
+STATE-INT8
+~~~~~~~~~~
+::
+
+      cond %{STATE-INT8:<n>}
+
+This condition allows you to check the state of an 8-bit unsigned integer.
+The ``<n>`` is the number of the integer, from 0 to 3. The current value of
+the state integer is returned, and all 4 integers are initialized to 0.
+
+STATE-INT16
+~~~~~~~~~~~
+::
+
+      cond %{STATE-INT16<:0>}
+
+This condition allows you to check the state of an 8-bit unsigned integer.
+There's only one 16-bit integer, and its value is returned. As such, the
+index, ``0``, is optional here.
+
 STATUS
 ~~~~~~
 ::
@@ -920,6 +960,38 @@ location automatically. This operator supports `String concatenations`_ for
 ``READ_RESPONSE_HDR_HOOK`` (the default when the plugin is global), the
 ``SEND_RESPONSE_HDR_HOOK``, or the ``REMAP_PSEUDO_HOOK``.
 
+set-state-flag
+~~~~~~~~~~~~~~
+::
+
+  set-state-flag <n> <value>
+
+This operator allows you to set the state of a flag. The ``<n>`` is the
+number of the flag, from 0 to 15. The ``<value>`` is either ``true`` or ``false``,
+turning the flag on or off.
+
+set-state-int8
+~~~~~~~~~~~~~~
+::
+
+   set-state-int8 <n> <value>
+
+This operator allows you to set the state of an 8-bit unsigned integer.
+The ``<n>`` is the number of the integer, from 0 to 3. The ``<value>`` is an
+unsigned 8-bit integer, 0-255. It can also be a condition, in which case the
+value of the condition is used.
+
+set-state-int16
+~~~~~~~~~~~~~~~
+::
+
+   set-state-int8 0 <value>
+
+This operator allows you to set the state of a 16-bit unsigned integer.
+The ``<value>`` is an unsigned 16-bit integer, 0-65535. It can also be a condition,
+in which case thevalue of the condition is used. The index, 0, is always required even
+though there is only one 16-bit integer state variable.
+
 set-status
 ~~~~~~~~~~
 ::
@@ -1438,6 +1510,11 @@ could each be tagged with a consistent name to make finding logs easier.::
 
 (Then in :file:`logging.yaml`, log ``%<{@PropertyName}cqh>``)
 
+.. note::
+    With the new ``state-flag``, ``state-int8`` and ``state-int16`` operators, you can
+    sometimes avoid setting internal ``@`` headers for passing information between hooks.
+    These internal state variables are much more efficient than setting and reading headers.
+
 Remove Client Query Parameters
 ------------------------------------
 

plugins/header_rewrite/conditions.cc

@@ -137,10 +137,7 @@ ConditionRandom::eval(const Resources & /* res ATS_UNUSED */)
 void
 ConditionRandom::append_value(std::string &s, const Resources & /* res ATS_UNUSED */)
 {
-  std::ostringstream oss;
-
-  oss << rand_r(&_seed) % _max;
-  s += oss.str();
+  s += std::to_string(rand_r(&_seed) % _max);
   Dbg(pi_dbg_ctl, "Appending RANDOM(%d) to evaluation value -> %s", _max, s.c_str());
 }
 
@@ -746,10 +743,7 @@ ConditionNow::set_qualifier(const std::string &q)
 void
 ConditionNow::append_value(std::string &s, const Resources & /* res ATS_UNUSED */)
 {
-  std::ostringstream oss;
-
-  oss << get_now_qualified(_now_qual);
-  s += oss.str();
+  s += std::to_string(get_now_qualified(_now_qual));
   Dbg(pi_dbg_ctl, "Appending NOW() to evaluation value -> %s", s.c_str());
 }
 
@@ -822,14 +816,11 @@ ConditionGeo::set_qualifier(const std::string &q)
 void
 ConditionGeo::append_value(std::string &s, const Resources &res)
 {
-  std::ostringstream oss;
-
   if (is_int_type()) {
-    oss << get_geo_int(TSHttpTxnClientAddrGet(res.txnp));
+    s += std::to_string(get_geo_int(TSHttpTxnClientAddrGet(res.txnp)));
   } else {
-    oss << get_geo_string(TSHttpTxnClientAddrGet(res.txnp));
+    s += get_geo_string(TSHttpTxnClientAddrGet(res.txnp));
   }
-  s += oss.str();
   Dbg(pi_dbg_ctl, "Appending GEO() to evaluation value -> %s", s.c_str());
 }
 
@@ -899,10 +890,7 @@ ConditionId::append_value(std::string &s, const Resources &res ATS_UNUSED)
 {
   switch (_id_qual) {
   case ID_QUAL_REQUEST: {
-    std::ostringstream oss;
-
-    oss << TSHttpTxnIdGet(res.txnp);
-    s += oss.str();
+    s += std::to_string(TSHttpTxnIdGet(res.txnp));
   } break;
   case ID_QUAL_PROCESS: {
     TSUuid process = TSProcessUuidGet();
@@ -1428,16 +1416,146 @@ ConditionNextHop::eval(const Resources &res)
 
 // ConditionHttpCntl: request header.
 void
-ConditionHttpCntl::initialize(Parser &p)
+ConditionHttpCntl::set_qualifier(const std::string &q)
+{
+  Condition::set_qualifier(q);
+
+  Dbg(pi_dbg_ctl, "\tParsing %%{HTTP-CNTL:%s}", q.c_str());
+  _http_cntl_qual = parse_http_cntl_qualifier(q);
+}
+
+void
+ConditionHttpCntl::append_value(std::string &s, const Resources &res)
+{
+  s += TSHttpTxnCntlGet(res.txnp, _http_cntl_qual) ? "TRUE" : "FALSE";
+  Dbg(pi_dbg_ctl, "Evaluating HTTP-CNTL(%s)", _qualifier.c_str());
+}
+
+bool
+ConditionHttpCntl::eval(const Resources &res)
+{
+  Dbg(pi_dbg_ctl, "Evaluating HTTP-CNTL()");
+  return TSHttpTxnCntlGet(res.txnp, _http_cntl_qual);
+}
+
+// ConditionStateFlag
+void
+ConditionStateFlag::set_qualifier(const std::string &q)
+{
+  Condition::set_qualifier(q);
+
+  _flag_ix = strtol(q.c_str(), nullptr, 10);
+  if (_flag_ix < 0 || _flag_ix >= NUM_STATE_FLAGS) {
+    TSError("[%s] STATE-FLAG index out of range: %s", PLUGIN_NAME, q.c_str());
+  } else {
+    Dbg(pi_dbg_ctl, "\tParsing %%{STATE-FLAG:%s}", q.c_str());
+    _mask = 1ULL << _flag_ix;
+  }
+}
+
+void
+ConditionStateFlag::append_value(std::string &s, const Resources &res)
+{
+  s += eval(res) ? "TRUE" : "FALSE";
+  Dbg(pi_dbg_ctl, "Evaluating STATE-FLAG(%d)", _flag_ix);
+}
+
+bool
+ConditionStateFlag::eval(const Resources &res)
+{
+  auto data = reinterpret_cast<uint64_t>(TSUserArgGet(res.txnp, _txn_slot));
+
+  Dbg(pi_dbg_ctl, "Evaluating STATE-FLAG()");
+
+  return (data & _mask) == _mask;
+}
+
+// ConditionStateInt8
+void
+ConditionStateInt8::initialize(Parser &p)
 {
   Condition::initialize(p);
+  MatcherType *match = new MatcherType(_cond_op);
+
+  match->set(static_cast<uint8_t>(strtol(p.get_arg().c_str(), nullptr, 10)), mods());
+  _matcher = match;
 }
 
 void
-ConditionHttpCntl::set_qualifier(const std::string &q)
+ConditionStateInt8::set_qualifier(const std::string &q)
 {
   Condition::set_qualifier(q);
 
-  Dbg(pi_dbg_ctl, "\tParsing %%{HTTP-CNTL:%s}", q.c_str());
-  _http_cntl_qual = parse_http_cntl_qualifier(q);
+  _byte_ix = strtol(q.c_str(), nullptr, 10);
+  if (_byte_ix < 0 || _byte_ix >= NUM_STATE_INT8S) {
+    TSError("[%s] STATE-INT8 index out of range: %s", PLUGIN_NAME, q.c_str());
+  } else {
+    Dbg(pi_dbg_ctl, "\tParsing %%{STATE-INT8:%s}", q.c_str());
+  }
+}
+
+void
+ConditionStateInt8::append_value(std::string &s, const Resources &res)
+{
+  uint8_t data = _get_data(res);
+
+  s += std::to_string(data);
+
+  Dbg(pi_dbg_ctl, "Appending STATE-INT8(%d) to evaluation value -> %s", data, s.c_str());
+}
+
+bool
+ConditionStateInt8::eval(const Resources &res)
+{
+  uint8_t data = _get_data(res);
+
+  Dbg(pi_dbg_ctl, "Evaluating STATE-INT8()");
+
+  return static_cast<const MatcherType *>(_matcher)->test(data);
+}
+
+// ConditionStateInt16
+void
+ConditionStateInt16::initialize(Parser &p)
+{
+  Condition::initialize(p);
+  MatcherType *match = new MatcherType(_cond_op);
+
+  match->set(static_cast<uint16_t>(strtol(p.get_arg().c_str(), nullptr, 10)), mods());
+  _matcher = match;
+}
+
+void
+ConditionStateInt16::set_qualifier(const std::string &q)
+{
+  Condition::set_qualifier(q);
+
+  if (!q.empty()) { // This qualifier is optional, but must be 0 if there
+    long ix = strtol(q.c_str(), nullptr, 10);
+
+    if (ix != 0) {
+      TSError("[%s] STATE-INT16 index out of range: %s", PLUGIN_NAME, q.c_str());
+    } else {
+      Dbg(pi_dbg_ctl, "\tParsing %%{STATE-INT16:%s}", q.c_str());
+    }
+  }
+}
+
+void
+ConditionStateInt16::append_value(std::string &s, const Resources &res)
+{
+  uint16_t data = _get_data(res);
+
+  s += std::to_string(data);
+  Dbg(pi_dbg_ctl, "Appending STATE-INT16(%d) to evaluation value -> %s", data, s.c_str());
+}
+
+bool
+ConditionStateInt16::eval(const Resources &res)
+{
+  uint16_t data = _get_data(res);
+
+  Dbg(pi_dbg_ctl, "Evaluating STATE-INT8()");
+
+  return static_cast<const MatcherType *>(_matcher)->test(data);
 }