[HICN-392] Assign independent suffixes for manifests/contents

This patch introduces a new class, SuffixStrategy and two sub-classes,
SuffixContent and SuffixManifest which allow to independently assign
suffixes to contents and manifests respectively. The produce() function
in socket_producer.cc has also been changed to use them.

Given a strategy and an offset (and optionally the capacity of a
manifest), these classes automatically compute the correct next
suffixes for both type of data (manifest or content). This removes
the burden of having to manage suffixes for instance when producing
or when retrieving content, and could be expanded to add more
strategy in the future.

Currently the only existing strategy is "INCREMENTAL": manifests
with capacity N have a suffix multiple of N+1: 0, N+1, 2(N+1) etc.
Contents have a suffix incremented by 1 except when it conflicts
with a manifest: 1, 2, ..., N, N+2, N+3, ..., 2N+1, 2N+3...

Signed-off-by: Olivier Roques <olvrqs@gmail.com>
Change-Id: Ia7692d7325240de7bea6e38b668077042e5f8758
Signed-off-by: Alberto Compagno <acompagn+fdio@cisco.com>

1 files changed, 134 insertions, 0 deletions

diff --git a/libtransport/src/hicn/transport/utils/suffix_strategy.h b/libtransport/src/hicn/transport/utils/suffix_strategy.h
new file mode 100644
index 000000000..99e557380
--- /dev/null
+++ b/libtransport/src/hicn/transport/utils/suffix_strategy.h
@@ -0,0 +1,134 @@
+/*
+ * Copyright (c) 2017-2019 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <hicn/transport/core/manifest_format.h>
+
+namespace utils {
+class SuffixStrategy {
+ public:
+  SuffixStrategy(
+      transport::core::NextSegmentCalculationStrategy suffix_stragegy,
+      std::uint32_t start_offset)
+      : suffix_stragegy_(suffix_stragegy),
+        suffix_(start_offset),
+        nb_segments_(0) {}
+
+  transport::core::NextSegmentCalculationStrategy getSuffixStrategy() {
+    return suffix_stragegy_;
+  }
+
+  std::uint32_t getSuffix() { return suffix_; }
+
+  virtual std::uint32_t getNextSuffix() = 0;
+
+  void updateSuffix(std::uint32_t new_suffix) { suffix_ = new_suffix; }
+
+  std::size_t getNbSegments() { return nb_segments_; }
+
+  void setNbSegments(std::size_t nb_segments) { nb_segments_ = nb_segments; }
+
+  void reset(std::uint32_t reset_suffix) {
+    suffix_ = reset_suffix;
+    nb_segments_ = 0;
+  }
+
+  ~SuffixStrategy() {}
+
+ protected:
+  transport::core::NextSegmentCalculationStrategy suffix_stragegy_;
+  std::uint32_t suffix_;
+  std::size_t nb_segments_;
+};
+
+class SuffixManifest : public SuffixStrategy {
+ public:
+  SuffixManifest(
+      transport::core::NextSegmentCalculationStrategy suffix_stragegy,
+      std::uint32_t start_offset)
+      : SuffixStrategy(suffix_stragegy, start_offset) {}
+
+  std::uint32_t getNextSuffix();
+
+  SuffixManifest operator++() {
+    uint32_t next_suffix = getNextSuffix();
+    updateSuffix(next_suffix);
+    return SuffixManifest(suffix_stragegy_, next_suffix);
+  }
+
+  SuffixManifest operator++(int) {
+    SuffixManifest temp_suffix(suffix_stragegy_, suffix_);
+    uint32_t next_suffix = getNextSuffix();
+    updateSuffix(next_suffix);
+    return temp_suffix;
+  }
+
+  SuffixManifest operator+(uint32_t shift) {
+    for (uint32_t i = 0; i < shift; i++) {
+      updateSuffix(getNextSuffix());
+    }
+    return SuffixManifest(suffix_stragegy_, getSuffix());
+  }
+};
+
+class SuffixContent : public SuffixStrategy {
+ public:
+  SuffixContent(transport::core::NextSegmentCalculationStrategy suffix_stragegy,
+                std::uint32_t start_offset, bool making_manifest)
+      : SuffixStrategy(suffix_stragegy, start_offset),
+        making_manifest_(making_manifest),
+        content_counter_(0) {}
+
+  SuffixContent(transport::core::NextSegmentCalculationStrategy suffix_stragegy,
+                std::uint32_t start_offset)
+      : SuffixContent(suffix_stragegy, start_offset, false) {}
+
+  std::uint32_t getNextSuffix();
+
+  SuffixContent operator++() {
+    uint32_t next_suffix = getNextSuffix();
+    updateSuffix(next_suffix);
+    return SuffixContent(suffix_stragegy_, next_suffix, making_manifest_);
+  }
+
+  SuffixContent operator++(int) {
+    SuffixContent temp_suffix(suffix_stragegy_, suffix_, making_manifest_);
+    uint32_t next_suffix = getNextSuffix();
+    updateSuffix(next_suffix);
+    return temp_suffix;
+  }
+
+  SuffixContent operator+(uint32_t shift) {
+    for (uint32_t i = 0; i < shift; i++) {
+      updateSuffix(getNextSuffix());
+    }
+    return SuffixContent(suffix_stragegy_, getSuffix(), making_manifest_);
+  }
+
+  void setUsingManifest(bool value) { making_manifest_ = value; }
+
+  void reset(std::uint32_t reset_suffix) {
+    SuffixStrategy::reset(reset_suffix);
+    content_counter_ = 0;
+  }
+
+ protected:
+  bool making_manifest_;
+  /* content_counter_ keeps track of the number of segments */
+  /* between two manifests */
+  uint32_t content_counter_;
+};
+}  // namespace utils