Dictionary with JudyHS and double linked list (#13032)

* dictionary internals isolation

* more dictionary cleanups

* added unit test

* we should use DICT internally

* disable cups in cmake

* implement DICTIONARY with Judy arrays

* operational JUDY implementation

* JUDY cleanup

* JUDY summary added

* JudyHS implementation with double linked list

* test negative searches too

* optimize destruction

* optimize set to insert first without lookup

* updated stats

* code cleanup; better organization; updated info

* more code cleanup and commenting

* more cleanup, renames and comments

* fix rename

* more cleanups

* use Judy.h from system paths

* added foreach traversal; added flag to add item in front; isolated locks to their own functions; destruction returns the number of bytes freed

* more comments; flags are now 16-bit

* completed unittesting

* addressed comments and added reference counters maintainance

* added unittest in main; tested removal of items in front, back and middle

* added read/write walkthrough and foreach; allowed walkthrough and foreach in write mode to delete the current element (used by cups.plugin); referenced counters removed from the API

* DICTFE.name should be const too

* added API calls for exposing all statistics

* dictionary flags as enum and reference counters as atomic operations

* more comments; improved error handling at unit tests

* added functions to allow unsafe access while traversing the dictionary with locks in place

* check for libcups in cmake

* added delete callback; implemented statsd with this dictionary

* added missing dfe_done()

* added alternative implementation with AVL

* added documentation

* added comments and warning about AVL

* dictionary walktrhough on new code

* simplified foreach; updated docs

* updated docs

* AVL is much faster without hashes

* AVL should follow DBENGINE

1 files changed, 33 insertions, 0 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3ed525fb52..cd5d68a8c5 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -231,6 +231,15 @@ pkg_check_modules(CURL libcurl)
 # ${CURL_INCLUDE_DIRS}
 
 # -----------------------------------------------------------------------------
+# Detect libcups
+
+pkg_check_modules(CURL libcups)
+# later we use:
+# ${CUPS_LIBRARIES}
+# ${CUPS_CFLAGS_OTHER}
+# ${CUPS_INCLUDE_DIRS}
+
+# -----------------------------------------------------------------------------
 # Detect libaws-c-common
 
 find_library(HAVE_AWS_CHECKSUMS aws-checksums)
@@ -491,6 +500,10 @@ set(SLABINFO_PLUGIN_FILES
         collectors/slabinfo.plugin/slabinfo.c
         )
 
+set(CUPS_PLUGIN_FILES
+        collectors/cups.plugin/cups_plugin.c
+        )
+
 set(EBPF_PROCESS_PLUGIN_FILES
         collectors/ebpf.plugin/ebpf.c
         collectors/ebpf.plugin/ebpf.h
@@ -1229,6 +1242,12 @@ ELSE()
     SET(ENABLE_PLUGIN_XENSTAT False)
 ENDIF()
 
+IF(CUPS_LIBRARIES)
+    SET(ENABLE_PLUGIN_CUPS True)
+ELSE()
+    SET(ENABLE_PLUGIN_CUPS False)
+ENDIF()
+
 
 # -----------------------------------------------------------------------------
 # netdatacli
@@ -1338,6 +1357,20 @@ ENDIF()
 
 
 # -----------------------------------------------------------------------------
+# cups.plugin
+
+IF(ENABLE_PLUGIN_CUPS)
+    message(STATUS "cups.plugin: enabled")
+    add_executable(cups.plugin config.h ${CUPS_PLUGIN_FILES})
+    target_link_libraries (cups.plugin libnetdata ${NETDATA_COMMON_LIBRARIES} ${CUPS_LIBRARIES})
+    target_include_directories(cups.plugin PUBLIC ${NETDATA_COMMON_INCLUDE_DIRS} ${CUPS_INCLUDE_DIRS})
+    target_compile_options(cups.plugin PUBLIC ${NETDATA_COMMON_CFLAGS} ${CUPS_CFLAGS_OTHER})
+ELSE()
+    message(STATUS "cups.plugin: disabled")
+ENDIF()
+
+
+# -----------------------------------------------------------------------------
 # cgroup-network
 
 IF(ENABLE_PLUGIN_CGROUP_NETWORK)