Merge "fiemap_writer: Add a progress notification."

am: dec436438a

Change-Id: I580c5f8efd0e3fe8147f782fa0bfdc5c895153bb

fs_mgr/libfiemap_writer/fiemap_writer.cpp

@@ -220,7 +220,7 @@ static bool PerformFileChecks(const std::string& file_path, uint64_t file_size,
 }
 
 static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blocksz,
-                         uint64_t file_size) {
+                         uint64_t file_size, std::function<bool(uint64_t, uint64_t)> on_progress) {
     // Reserve space for the file on the file system and write it out to make sure the extents
     // don't come back unwritten. Return from this function with the kernel file offset set to 0.
     // If the filesystem is f2fs, then we also PIN the file on disk to make sure the blocks
@@ -245,12 +245,22 @@ static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blo
         return false;
     }
 
+    int permille = -1;
     for (; offset < file_size; offset += blocksz) {
         if (!::android::base::WriteFully(file_fd, buffer.get(), blocksz)) {
             PLOG(ERROR) << "Failed to write" << blocksz << " bytes at offset" << offset
                         << " in file " << file_path;
             return false;
         }
+        // Don't invoke the callback every iteration - wait until a significant
+        // chunk (here, 1/1000th) of the data has been processed.
+        int new_permille = (static_cast<uint64_t>(offset) * 1000) / file_size;
+        if (new_permille != permille) {
+            if (on_progress && !on_progress(offset, file_size)) {
+                return false;
+            }
+            permille = new_permille;
+        }
     }
 
     if (lseek64(file_fd, 0, SEEK_SET) < 0) {
@@ -264,6 +274,10 @@ static bool AllocateFile(int file_fd, const std::string& file_path, uint64_t blo
         return false;
     }
 
+    // Send one last progress notification.
+    if (on_progress && !on_progress(file_size, file_size)) {
+        return false;
+    }
     return true;
 }
 
@@ -412,7 +426,8 @@ static bool ReadFiemap(int file_fd, const std::string& file_path,
     return last_extent_seen;
 }
 
-FiemapUniquePtr FiemapWriter::Open(const std::string& file_path, uint64_t file_size, bool create) {
+FiemapUniquePtr FiemapWriter::Open(const std::string& file_path, uint64_t file_size, bool create,
+                                   std::function<bool(uint64_t, uint64_t)> progress) {
     // if 'create' is false, open an existing file and do not truncate.
     int open_flags = O_RDWR | O_CLOEXEC;
     if (create) {
@@ -474,7 +489,7 @@ FiemapUniquePtr FiemapWriter::Open(const std::string& file_path, uint64_t file_s
     }
 
     if (create) {
-        if (!AllocateFile(file_fd, abs_path, blocksz, file_size)) {
+        if (!AllocateFile(file_fd, abs_path, blocksz, file_size, std::move(progress))) {
             LOG(ERROR) << "Failed to allocate file: " << abs_path << " of size: " << file_size
                        << " bytes";
             cleanup(abs_path, create);

fs_mgr/libfiemap_writer/fiemap_writer_test.cpp

@@ -83,6 +83,25 @@ TEST_F(FiemapWriterTest, CheckFilePath) {
     EXPECT_EQ(access(testfile.c_str(), F_OK), 0);
 }
 
+TEST_F(FiemapWriterTest, CheckProgress) {
+    std::vector<uint64_t> expected{
+            0,
+            4096,
+    };
+    size_t invocations = 0;
+    auto callback = [&](uint64_t done, uint64_t total) -> bool {
+        EXPECT_LT(invocations, expected.size());
+        EXPECT_EQ(done, expected[invocations]);
+        EXPECT_EQ(total, 4096);
+        invocations++;
+        return true;
+    };
+
+    auto ptr = FiemapWriter::Open(testfile, 4096, true, std::move(callback));
+    EXPECT_NE(ptr, nullptr);
+    EXPECT_EQ(invocations, 2);
+}
+
 TEST_F(FiemapWriterTest, CheckBlockDevicePath) {
     FiemapUniquePtr fptr = FiemapWriter::Open(testfile, 4096);
     EXPECT_EQ(fptr->size(), 4096);

fs_mgr/libfiemap_writer/include/libfiemap_writer/fiemap_writer.h

@@ -21,6 +21,7 @@
 #include <sys/types.h>
 #include <unistd.h>
 
+#include <functional>
 #include <string>
 #include <vector>
 
@@ -36,9 +37,13 @@ class FiemapWriter final {
   public:
     // Factory method for FiemapWriter.
     // The method returns FiemapUniquePtr that contains all the data necessary to be able to write
-    // to the given file directly using raw block i/o.
+    // to the given file directly using raw block i/o. The optional progress callback will be
+    // invoked, if create is true, while the file is being initialized. It receives the bytes
+    // written and the number of total bytes. If the callback returns false, the operation will
+    // fail.
     static FiemapUniquePtr Open(const std::string& file_path, uint64_t file_size,
-                                bool create = true);
+                                bool create = true,
+                                std::function<bool(uint64_t, uint64_t)> progress = {});
 
     // Syncs block device writes.
     bool Flush() const;