feat: format the code with clang-format

The code currently mixes tab and space indenting.

Having the code style defined into a file is usually good practice, as
we can use tools to do it automatically.

This change proposes use clang-format to do it. It provides predefined
rules following LLVM/Google/Mozilla/GNU code style that can be tweaked.

I try to create a .clang-format configuration that just fix the
tab/space mix and keep the rest as-is as much I can.

Currently all cpp/hpp/h are formatted except those in src/ext.

The code formatting will be checked Jenkins.
It also can be run with: `cmake .. && make clang-format`

cmake also install automatically a pre-commit hook to format the code.
It can be disabled with `INSTALL_GIT_HOOKS=OFF`

llvm provide some basic integration for editor:

https://clang.llvm.org/docs/ClangFormat.html#vim-integration
https://clang.llvm.org/docs/ClangFormat.html#emacs-integration

But you can also use other tools like:

https://github.com/SavchenkoValeriy/emacs-clang-format-plus

Author: sileht

.clang-format

@@ -0,0 +1,135 @@
+---
+Language:        Cpp
+AccessModifierOffset: -2
+AlignAfterOpenBracket: Align
+AlignConsecutiveMacros: false
+AlignConsecutiveAssignments: false
+AlignConsecutiveDeclarations: false
+AlignEscapedNewlines: Right
+AlignOperands:   true
+AlignTrailingComments: true
+AllowAllArgumentsOnNextLine: true
+AllowAllConstructorInitializersOnNextLine: true
+AllowAllParametersOfDeclarationOnNextLine: true
+AllowShortBlocksOnASingleLine: Never
+AllowShortCaseLabelsOnASingleLine: false
+AllowShortFunctionsOnASingleLine: None
+AllowShortLambdasOnASingleLine: All
+AllowShortIfStatementsOnASingleLine: Never
+AllowShortLoopsOnASingleLine: false
+AlwaysBreakAfterDefinitionReturnType: None
+AlwaysBreakAfterReturnType: None
+AlwaysBreakBeforeMultilineStrings: false
+AlwaysBreakTemplateDeclarations: MultiLine
+BinPackArguments: true
+BinPackParameters: true
+BraceWrapping:
+  AfterCaseLabel:  true
+  AfterClass:      true
+  AfterControlStatement: true
+  AfterEnum:       true
+  AfterFunction:   true
+  AfterNamespace:  true
+  AfterObjCDeclaration: true
+  AfterStruct:     true
+  AfterUnion:      true
+  AfterExternBlock: true
+  BeforeCatch:     true
+  BeforeElse:      true
+  IndentBraces:    true
+  SplitEmptyFunction: true
+  SplitEmptyRecord: true
+  SplitEmptyNamespace: true
+BreakBeforeBinaryOperators: All
+BreakBeforeBraces: GNU
+BreakBeforeInheritanceComma: false
+BreakInheritanceList: BeforeColon
+BreakBeforeTernaryOperators: true
+BreakConstructorInitializersBeforeComma: false
+BreakConstructorInitializers: BeforeColon
+BreakAfterJavaFieldAnnotations: false
+BreakStringLiterals: true
+ColumnLimit:     79
+CommentPragmas:  '^ IWYU pragma:'
+CompactNamespaces: false
+ConstructorInitializerAllOnOneLineOrOnePerLine: false
+ConstructorInitializerIndentWidth: 4
+ContinuationIndentWidth: 4
+Cpp11BracedListStyle: false
+DeriveLineEnding: true
+DerivePointerAlignment: false
+DisableFormat:   false
+ExperimentalAutoDetectBinPacking: false
+FixNamespaceComments: false
+ForEachMacros:
+  - foreach
+  - Q_FOREACH
+  - BOOST_FOREACH
+IncludeBlocks:   Preserve
+IncludeCategories:
+  - Regex:           '^"(llvm|llvm-c|clang|clang-c)/'
+    Priority:        2
+    SortPriority:    0
+  - Regex:           '^(<|"(gtest|gmock|isl|json)/)'
+    Priority:        3
+    SortPriority:    0
+  - Regex:           '.*'
+    Priority:        1
+    SortPriority:    0
+IncludeIsMainRegex: '(Test)?$'
+IncludeIsMainSourceRegex: ''
+IndentCaseLabels: false
+IndentGotoLabels: true
+IndentPPDirectives: None
+IndentWidth:     2
+IndentWrappedFunctionNames: false
+JavaScriptQuotes: Leave
+JavaScriptWrapImports: true
+KeepEmptyLinesAtTheStartOfBlocks: true
+MacroBlockBegin: ''
+MacroBlockEnd:   ''
+MaxEmptyLinesToKeep: 1
+NamespaceIndentation: All
+ObjCBinPackProtocolList: Auto
+ObjCBlockIndentWidth: 2
+ObjCSpaceAfterProperty: false
+ObjCSpaceBeforeProtocolList: true
+PenaltyBreakAssignment: 2
+PenaltyBreakBeforeFirstCallParameter: 19
+PenaltyBreakComment: 300
+PenaltyBreakFirstLessLess: 120
+PenaltyBreakString: 1000
+PenaltyBreakTemplateDeclaration: 10
+PenaltyExcessCharacter: 1000000
+PenaltyReturnTypeOnItsOwnLine: 60
+PointerAlignment: Right
+ReflowComments:  true
+SortIncludes:    false
+SortUsingDeclarations: true
+SpaceAfterCStyleCast: false
+SpaceAfterLogicalNot: false
+SpaceAfterTemplateKeyword: true
+SpaceBeforeAssignmentOperators: true
+SpaceBeforeCpp11BracedList: false
+SpaceBeforeCtorInitializerColon: true
+SpaceBeforeInheritanceColon: true
+SpaceBeforeParens: ControlStatements
+SpaceBeforeRangeBasedForLoopColon: true
+SpaceInEmptyBlock: false
+SpaceInEmptyParentheses: false
+SpacesBeforeTrailingComments: 1
+SpacesInAngles:  false
+SpacesInConditionalStatement: false
+SpacesInContainerLiterals: true
+SpacesInCStyleCastParentheses: false
+SpacesInParentheses: false
+SpacesInSquareBrackets: false
+SpaceBeforeSquareBrackets: false
+Standard:        c++11
+StatementMacros:
+  - Q_UNUSED
+  - QT_REQUIRE_VERSION
+TabWidth:        8
+UseCRLF:         false
+UseTab:          Never
+...

CMakeLists.txt

@@ -1011,6 +1011,34 @@ if (BUILD_TOOLS)
   add_subdirectory(tools)
 endif()
 
+# Get all project files
+file(GLOB_RECURSE ALL_SOURCE_FILES src/*.cpp src/*.hpp src/*.h src/*.c tests/*.cc src/*.cc)
+list(FILTER ALL_SOURCE_FILES EXCLUDE REGEX "^${CMAKE_SOURCE_DIR}/src/ext/.*$")
+
+add_custom_target(
+        clang-format
+        COMMAND clang-format
+        -style=file
+        -i
+        ${ALL_SOURCE_FILES}
+)
+add_custom_target(
+        clang-format-check
+        COMMAND clang-format
+        --dry-run
+        --Werror
+        --ferror-limit=10
+        -style=file
+        -i
+        ${ALL_SOURCE_FILES}
+)
+
+option(INSTALL_GIT_HOOKS "install client side git hook" ON)
+if (INSTALL_GIT_HOOKS)
+    configure_file(${CMAKE_CURRENT_SOURCE_DIR}/tools/git-pre-commit-hook
+                   ${CMAKE_CURRENT_SOURCE_DIR}/.git/hooks/pre-commit @ONLY)
+endif()
+
 # status
 message(STATUS "Build Tests          : ${BUILD_TESTS}")
 message(STATUS "Caffe DEBUG          : ${USE_CAFFE_DEBUG}")

Jenkinsfile

@@ -8,6 +8,7 @@ export PATH="/usr/lib/ccache/:$PATH"
 mkdir -p build
 cd build
 cmake .. -DBUILD_TESTS=ON -DUSE_CUDNN=ON -DUSE_SIMSEARCH=ON -DUSE_TSNE=ON -DUSE_XGBOOST=ON -DUSE_TORCH=ON -DUSE_NCNN=ON -DUSE_TENSORRT=ON -DCUDA_ARCH="-gencode arch=compute_61,code=sm_61"
+make clang-format-check
 make -j24
 ccache -s
 '''

README.md

@@ -200,7 +200,7 @@ http://www.deepdetect.com/overview/examples/
 |                          | Caffe | Tensorflow | Source        | Top-1 Accuracy (ImageNet) |
 |--------------------------|-------|------------|---------------|---------------------------|
 | AlexNet                  | Y     | N          | BVLC          |          57.1%                 |
-| SqueezeNet               | [Y](https://deepdetect.com/models/squeezenet/squeezenet_v1.1.caffemodel)     | N          | DeepScale              |       59.5%                    | 
+| SqueezeNet               | [Y](https://deepdetect.com/models/squeezenet/squeezenet_v1.1.caffemodel)     | N          | DeepScale              |       59.5%                    |
 | Inception v1 / GoogleNet | [Y](https://deepdetect.com/models/ggnet/bvlc_googlenet.caffemodel)     | [Y](https://deepdetect.com/models/tf/inception_v1.pb)          | BVLC / Google |             67.9%              |
 | Inception v2             | N     | [Y](https://deepdetect.com/models/tf/inception_v2.pb)          | Google        |     72.2%                      |
 | Inception v3             | N     | [Y](https://deepdetect.com/models/tf/inception_v3.pb)          | Google        |         76.9%                  |
@@ -263,7 +263,7 @@ Beware of dependencies, typically on Debian/Ubuntu Linux, do:
 sudo apt-get install build-essential libgoogle-glog-dev libgflags-dev libeigen3-dev libopencv-dev libcppnetlib-dev libboost-dev libboost-iostreams-dev libcurlpp-dev libcurl4-openssl-dev protobuf-compiler libopenblas-dev libhdf5-dev libprotobuf-dev libleveldb-dev libsnappy-dev liblmdb-dev libutfcpp-dev cmake libgoogle-perftools-dev unzip python-setuptools python-dev libspdlog-dev python-six python-enum34 libarchive-dev
 ```
 
-#### Choosing interfaces : 
+#### Choosing interfaces :
 
 DeepDetect can be used:
 - directly from command line for caffe models. To build the executable use:
@@ -274,7 +274,7 @@ cmake .. -DUSE_COMMAND_LINE=ON
 ```
 cmake .. -DUSE_COMMAND_LINE=ON -DUSE_JSON_API=ON
 ```
-- as a REST server (using JSON API). To build the server executable use (`USE_JSON_API` is auto-selected): 
+- as a REST server (using JSON API). To build the server executable use (`USE_JSON_API` is auto-selected):
 ```
 cmake .. -DUSE_HTTP_SERVER=ON
 ```
@@ -383,7 +383,7 @@ Specify the following option via cmake:
 ```$xslt
 cmake .. -DUSE_TENSORRT=ON
 ```
-TensorRT requires GPU and CUDNN, they are automatically switched on. 
+TensorRT requires GPU and CUDNN, they are automatically switched on.
 
 #### Build with TensorRT support + TRT oss parts
 Specify the following option via cmake:
@@ -442,6 +442,19 @@ Run tests with:
 ctest
 ```
 
+### Code Style Rules
+
+`clang-format` is used to enforce code style.
+
+You can automatically format it with:
+
+```
+cmake ..
+make clang-format
+```
+
+Or use your favorite editor with a clang-format plugin.
+
 ### Start the server
 
 ```
@@ -481,7 +494,7 @@ where `sname` is the service name and the JSON is a string without external quot
 - service prediction
 ```
 service_predict;JSON string
-``` 
+```
 
 ### Pure command line JSON API
 
@@ -502,7 +515,7 @@ where `<other options>` stands for the command line parameters from the command
 -service_train (/train POST call JSON string) type: string default: ""
 -service_train_delete (/train DELETE call JSON string) type: string default: ""
 -service_train_status (/train GET call JSON string) type: string default: ""
-							  
+
 ```
 
 The options above can be obtained from running