[EROFS] test: add verification for file contents

This adds test case 002. The previous stress test was only
for empty files; this patch generates small files with random
content.

Signed-off-by: Hongzhen Luo <hongzhen@linux.alibaba.com>

Author: Hongzhen Luo

src/overlaybd/tar/erofs/test/erofs_stress.cpp

@@ -17,13 +17,71 @@
 #include <gtest/gtest.h>
 #include <photon/photon.h>
 #include <photon/common/alog-stdstring.h>
+#include <random>
+#include <functional>
 #include "erofs_stress_base.h"
 
 #define EROFS_STRESS_UNIMPLEMENTED_FUNC(ret_type, func, ret) \
 ret_type func override { \
       return ret; \
 }
 
+class StressInterImpl: public StressGenInter {
+public:
+	int max_file_size = SECTOR_SIZE * 128;
+	int min_file_size = SECTOR_SIZE;
+	int block_size = 4096;
+	std::hash<std::string> hash_fn;
+
+	/* generate file content in build phase */
+	bool build_gen_content(StressNode *node, StressHostFile *file) override {
+		std::random_device rd;
+		std::mt19937 gen(rd());
+		std::uniform_int_distribution<> dis(min_file_size, max_file_size);
+		int size =  dis(gen);
+		int len;
+		off64_t offset = 0;
+		std::string hash_val;
+
+		while (size > 0) {
+				len = std::min(size, block_size);
+				std::string block_str = get_randomstr(len, false);
+				if (file->file->pwrite(block_str.c_str(), len, offset) != len)
+						LOG_ERROR_RETURN(-1, -1, "fail to write to host file `", file->path);
+				hash_val = std::to_string(hash_fn(hash_val + block_str));
+				size -= len;
+				offset += len;
+		}
+		node->content = hash_val;
+		return true;
+	}
+
+	/* generate node content in verify phase */
+	bool verify_gen_content(StressNode *node, photon::fs::IFile *erofs_file) override {
+		std::string hash_val;
+		char buf[block_size];
+		struct stat st;
+		off_t left, offset = 0;
+		int len;
+
+		if (erofs_file->fstat(&st))
+				LOG_ERROR_RETURN(-1, -1, "fail to stat file");
+		left = st.st_size;
+		while (left > 0) {
+				len = std::min((off_t)block_size, left);
+				if (len != erofs_file->pread(buf, len, offset))
+						LOG_ERROR_RETURN(-1, -1, "fail to pread file");
+
+				std::string block_str(buf, len);
+				hash_val = std::to_string(hash_fn(hash_val + block_str));
+				left -= len;
+				offset += len;
+		}
+		node->content = hash_val;
+		return true;
+	}
+};
+
 /*
  * TC001
  *
@@ -62,6 +120,48 @@ class StressCase001: public StressBase {
 	}
 };
 
+/*
+ * TC002
+ *
+ * Create layers, each layer contains 2 dirs,
+ * each dir contains 10 files.
+ *
+ * Testing the integrity of file contents.
+ */
+class StressCase002: public StressBase, public StressInterImpl {
+public:
+	StressCase002(std::string path, int layers): StressBase(path, layers) {}
+
+	/* leave mod/own/xattr empty */
+	EROFS_STRESS_UNIMPLEMENTED_FUNC(bool, build_gen_mod(StressNode *node, StressHostFile *file), true)
+	EROFS_STRESS_UNIMPLEMENTED_FUNC(bool, build_gen_own(StressNode *node, StressHostFile *file), true)
+	EROFS_STRESS_UNIMPLEMENTED_FUNC(bool, build_gen_xattrs(StressNode *node, StressHostFile *file), true)
+	bool build_gen_content(StressNode *node, StressHostFile *file) override {
+		return StressInterImpl::build_gen_content(node, file);
+	}
+
+	/* leave mod/own/xattr empty */
+	EROFS_STRESS_UNIMPLEMENTED_FUNC(bool, verify_gen_mod(StressNode *node, photon::fs::IFile *erofs_file), true)
+	EROFS_STRESS_UNIMPLEMENTED_FUNC(bool, verify_gen_own(StressNode *node, photon::fs::IFile *erofs_file), true)
+	EROFS_STRESS_UNIMPLEMENTED_FUNC(bool, verify_gen_xattrs(StressNode *node, photon::fs::IFile *erofs_file), true)
+	bool verify_gen_content(StressNode *node, photon::fs::IFile *erofs_file) override {
+		return StressInterImpl::verify_gen_content(node, erofs_file);
+	}
+
+	/*
+	 * each layer has two dirs:
+	 * dir one contains 10 files,
+	 * dir two contains 10 files
+	 */
+	std::vector<int> layer_dirs(int idx) {
+		std::vector<int> ret;
+
+		ret.emplace_back(10);
+		ret.emplace_back(10);
+		return ret;
+	}
+};
+
 TEST(ErofsStressTest, TC001) {
 	std::srand(static_cast<unsigned int>(std::time(0)));
 	StressCase001 *tc001 = new StressCase001("./erofs_stress_001", 20);
@@ -70,6 +170,14 @@ TEST(ErofsStressTest, TC001) {
 	delete tc001;
 }
 
+TEST(ErofsStressTest, TC002) {
+	std::srand(static_cast<unsigned int>(std::time(0)));
+	StressCase002 *tc002 = new StressCase002("./erofs_stress_002", 10);
+
+	ASSERT_EQ(tc002->run(), true);
+	delete tc002;
+}
+
 int main(int argc, char **argv) {
 
 	::testing::InitGoogleTest(&argc, argv);

src/overlaybd/tar/erofs/test/erofs_stress_base.h

@@ -25,6 +25,7 @@
 #include <gtest/gtest.h>
 #include <fcntl.h>
 #include "../../../lsmt/file.h"
+#include "../erofs_fs.h"
 
 #define IMAGE_SIZE 1UL<<30
 #define SECTOR_SIZE 512ULL