Add support for code format checking using rustfmt in optional

pre-commit hook and in ci pipeline. Found issues can be fixed
automatically via make fmt.

.circleci/config.yml

@@ -10,6 +10,16 @@ executors:
       - image: cimg/rust:1.52.1
 
 jobs:
+  check-codestyle:
+    executor: zenith-build-executor
+    steps:
+      - checkout
+
+      - run:
+          name: rustfmt
+          when: always
+          command: |
+            cargo fmt --all -- --check
 
   # A job to build postgres
   build-postgres:
@@ -257,6 +267,7 @@ jobs:
 workflows:
   build_and_test:
     jobs:
+      - check-codestyle
       - build-postgres
       - build-zenith:
           name: build-zenith-<< matrix.build_type >>

Makefile

@@ -67,4 +67,14 @@ distclean:
 	rm -rf tmp_install
 	cargo clean
 
+fmt:
+	@files=$$(git diff --cached --name-only --diff-filter=ACM | grep ".rs"); \
+	if [ "$$files" ]; then \
+		rustfmt $$files --edition=2018; \
+	fi;
+
+
+setup-pre-commit-hook:
+	ln -s -f ../../pre-commit.sh.tpl .git/hooks/pre-commit
+
 .PHONY: postgres-configure postgres postgres-headers zenith

pre-commit.sh.tpl

@@ -0,0 +1,34 @@
+#!/bin/bash
+
+RED='\033[0;31m'
+GREEN='\033[0;33m'
+CYAN='\033[0;36m'
+NC='\033[0m' # No Color
+
+function check {
+    name=$1
+    prefix=$2
+    files=$(git diff --cached --name-only --diff-filter=ACM | grep $prefix)
+    shift; shift;
+    echo -n "checking $name ";
+    if [ -z "$files" ]; then 
+        echo -e "${CYAN}[NOT APPLICABLE]${NC}"
+        exit 0;
+    fi
+
+    cd $(git rev-parse --show-toplevel)
+    
+    out=$($@ $files)
+    if [ $? -eq 0 ];
+    then
+        echo -e "${GREEN}[OK]${NC}"
+        cd -
+    else
+        echo -e "${RED}[FAILED]${NC}"
+        echo -e "Please inspect the output below and run make fmt to fix automatically\n"
+        echo -e "$out"
+        exit 1
+    fi
+}
+
+check rustfmt .rs rustfmt --check --edition=2018