Add support for CMCD-Request header nor field to prefetch plugin

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

@@ -170,6 +170,29 @@ specified with an integer followed by a colon, e.g. ``{8:$2+2}``,
 causing the resulting number to be padded with leading zeroes if it
 has fewer digits than the width.
 
+CMCD (Common Media Client Data) CMCD-Request header with nor field
+------------------------------------------------------------------
+
+If the ``--cmcd-nor`` option is specified the Cmcd-Request header with nor field is handled.
+
+With setup ::
+
+  map http://example.com http://origin.com \
+      @plugin=cachekey.so @pparam=--remove-all-params=true \
+      @plugin=prefetch.so \
+          @pparam=--cmcd-nor=true
+
+If the incoming request is ::
+
+  http://example-seed.com/path/someitem.m4a
+
+with header ::
+
+  Cmcd-Request: nor="otheritem.m4a"
+
+The following URL will be requested to be prefetched ::
+
+  http://example-seed.com/path/otheritem.m4a
 
 Overhead from **next object** prefetch
 --------------------------------------
@@ -238,6 +261,7 @@ Plugin parameters
   - ``true`` - configures the plugin run on the **front-tier**,
   - ``false`` - to be run on the **back-tier**.
 * ``--api-header`` - the header used by the plugin internally, also used to mark a prefetch request to the next tier in dual-tier usage.
+* ``--cmcd-nor`` - prefetch for a Cmcd-Request header with nor field.
 * ``--fetch-policy`` - fetch policy
   - ``simple`` - this policy just makes sure there are no same concurrent prefetches triggered (default and always used in combination with any other policy)
   - ``lru:n`` - this policy uses LRU to identify "hot" objects and triggers prefetch if the object is not found. `n` is the size of the LRU

plugins/prefetch/common.h

@@ -31,6 +31,7 @@
 #include <vector>
 
 typedef std::string String;
+typedef std::string_view StringView;
 typedef std::set<std::string> StringSet;
 typedef std::list<std::string> StringList;
 typedef std::vector<std::string> StringVector;

plugins/prefetch/configs.cc

@@ -57,6 +57,7 @@ PrefetchConfig::init(int argc, char *argv[])
   static const struct option longopt[] = {
     {const_cast<char *>("front"),              optional_argument, nullptr, 'f'},
     {const_cast<char *>("api-header"),         optional_argument, nullptr, 'h'},
+    {const_cast<char *>("cmcd-nor"),           optional_argument, nullptr, 'd'},
     {const_cast<char *>("next-header"),        optional_argument, nullptr, 'n'},
     {const_cast<char *>("fetch-policy"),       optional_argument, nullptr, 'p'},
     {const_cast<char *>("fetch-count"),        optional_argument, nullptr, 'c'},
@@ -68,15 +69,15 @@ PrefetchConfig::init(int argc, char *argv[])
     {const_cast<char *>("metrics-prefix"),     optional_argument, nullptr, 'm'},
     {const_cast<char *>("exact-match"),        optional_argument, nullptr, 'y'},
     {const_cast<char *>("log-name"),           optional_argument, nullptr, 'l'},
-    {nullptr,                                  0,                 nullptr, 0  }
+    {nullptr,                                  0,                 nullptr, 0  },
   };
 
   bool status = true;
   optind      = 0;
 
   /* argv contains the "to" and "from" URLs. Skip the first so that the second one poses as the program name. */
-  argc--;
-  argv++;
+  --argc;
+  ++argv;
 
   for (;;) {
     int opt;
@@ -97,6 +98,10 @@ PrefetchConfig::init(int argc, char *argv[])
       setApiHeader(optarg);
       break;
 
+    case 'd': /* --cmcd-nor */
+      _cmcd_nor = ::isTrue(optarg);
+      break;
+
     case 'n': /* --next-header */
       setNextHeader(optarg);
       break;
@@ -167,6 +172,7 @@ PrefetchConfig::finalize()
   PrefetchDebug("front-end: %s", (_front ? "true" : "false"));
   PrefetchDebug("exact match: %s", (_exactMatch ? "true" : "false"));
   PrefetchDebug("query key: %s", _queryKey.c_str());
+  PrefetchDebug("cncd-nor: %s", (_front ? "true" : "false"));
   PrefetchDebug("API header name: %s", _apiHeader.c_str());
   PrefetchDebug("next object header name: %s", _nextHeader.c_str());
   PrefetchDebug("fetch policy parameters: %s", _fetchPolicy.c_str());

plugins/prefetch/configs.h

@@ -35,8 +35,8 @@ class PrefetchConfig
 {
 public:
   PrefetchConfig()
-    : _apiHeader("X-AppleCDN-Prefetch"),
-      _nextHeader("X-AppleCDN-Prefetch-Next"),
+    : _apiHeader("X-CDN-Prefetch"),
+      _nextHeader("X-CDN-Prefetch-Next"),
       _replaceHost(),
       _namespace("default"),
       _metricsPrefix("prefetch.stats")
@@ -111,6 +111,12 @@ class PrefetchConfig
     return _exactMatch;
   }
 
+  bool
+  isCmcdNor() const
+  {
+    return _cmcd_nor;
+  }
+
   void
   setFetchCount(const char *optarg)
   {
@@ -208,5 +214,6 @@ class PrefetchConfig
   unsigned _fetchMax   = 0;
   bool _front          = false;
   bool _exactMatch     = false;
+  bool _cmcd_nor       = false;
   MultiPattern _nextPaths;
 };

plugins/prefetch/fetch.cc

@@ -409,11 +409,12 @@ BgFetch::~BgFetch()
 
 bool
 BgFetch::schedule(BgFetchState *state, const PrefetchConfig &config, bool askPermission, TSMBuffer requestBuffer,
-                  TSMLoc requestHeaderLoc, TSHttpTxn txnp, const char *path, size_t pathLen, const String &cachekey)
+                  TSMLoc requestHeaderLoc, TSHttpTxn txnp, const char *path, size_t pathLen, const String &cachekey,
+                  bool removeQuery)
 {
   bool ret       = false;
   BgFetch *fetch = new BgFetch(state, config, askPermission);
-  if (fetch->init(requestBuffer, requestHeaderLoc, txnp, path, pathLen, cachekey)) {
+  if (fetch->init(requestBuffer, requestHeaderLoc, txnp, path, pathLen, cachekey, removeQuery)) {
     fetch->schedule();
     ret = true;
   } else {
@@ -451,7 +452,7 @@ BgFetch::addBytes(int64_t b)
  */
 bool
 BgFetch::init(TSMBuffer reqBuffer, TSMLoc reqHdrLoc, TSHttpTxn txnp, const char *fetchPath, size_t fetchPathLen,
-              const String &cachekey)
+              const String &cachekey, bool removeQuery)
 {
   TSAssert(TS_NULL_MLOC == _headerLoc);
   TSAssert(TS_NULL_MLOC == _urlLoc);
@@ -506,6 +507,15 @@ BgFetch::init(TSMBuffer reqBuffer, TSMLoc reqHdrLoc, TSHttpTxn txnp, const char
     return false;
   }
 
+  /* Remove the query string */
+  if (removeQuery) {
+    if (TS_SUCCESS == TSUrlHttpQuerySet(_mbuf, _urlLoc, "", 0)) {
+      PrefetchDebug("original query string removed");
+    } else {
+      PrefetchError("failed to remove original query string");
+    }
+  }
+
   /* Now set or remove the prefetch API header */
   const String &header = _config.getApiHeader();
   if (_config.isFront()) {

plugins/prefetch/fetch.h

@@ -169,13 +169,14 @@ class BgFetch
 {
 public:
   static bool schedule(BgFetchState *state, const PrefetchConfig &config, bool askPermission, TSMBuffer requestBuffer,
-                       TSMLoc requestHeaderLoc, TSHttpTxn txnp, const char *path, size_t pathLen, const String &cachekey);
+                       TSMLoc requestHeaderLoc, TSHttpTxn txnp, const char *path, size_t pathLen, const String &cachekey,
+                       bool removeQuery = false);
 
 private:
   BgFetch(BgFetchState *state, const PrefetchConfig &config, bool lock);
   ~BgFetch();
   bool init(TSMBuffer requestBuffer, TSMLoc requestHeaderLoc, TSHttpTxn txnp, const char *fetchPath, size_t fetchPathLen,
-            const String &cacheKey);
+            const String &cacheKey, bool removeQuery = false);
   void schedule();
   static int handler(TSCont contp, TSEvent event, void * /* edata ATS_UNUSED */);
   bool saveIp(TSHttpTxn txnp);