X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=store.cc;h=26797b319ed635341d1deeedf6bd161110644590;hb=ac33ae99de4a6aa9cfaca2f7fd6746758264758e;hp=ce91e55621d210f82df9a06f9cbaa3c08eb2ff5c;hpb=08147fb0bc1d09610b05f3f7d54eda88ef5776ec;p=cumulus.git

diff --git a/store.cc b/store.cc
index ce91e55..26797b3 100644
--- a/store.cc
+++ b/store.cc
@@ -10,6 +10,8 @@
 #include <stdio.h>
 #include <sys/types.h>
 #include <sys/stat.h>
+#include <sys/resource.h>
+#include <sys/wait.h>
 #include <unistd.h>
 #include <fcntl.h>
 #include <time.h>
@@ -26,21 +28,96 @@ using std::list;
 using std::set;
 using std::string;
 
+static char *const filter_program[] = {"bzip2", "-c", NULL};
+
+static void cloexec(int fd)
+{
+    long flags = fcntl(fd, F_GETFD);
+
+    if (flags < 0)
+        return;
+
+    fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+}
+
 Tarfile::Tarfile(const string &path, const string &segment)
     : size(0),
       segment_name(segment)
 {
-    if (tar_open(&t, (char *)path.c_str(), NULL, O_WRONLY | O_CREAT, 0600,
-                 TAR_VERBOSE | TAR_GNU) == -1)
+    real_fd = open(path.c_str(), O_WRONLY | O_CREAT, 0600);
+    if (real_fd < 0)
+        throw IOException("Error opening output file");
+
+    filter_fd = spawn_filter(real_fd);
+
+    if (tar_fdopen(&t, filter_fd, (char *)path.c_str(), NULL,
+                   O_WRONLY | O_CREAT, 0600, TAR_VERBOSE | TAR_GNU) == -1)
         throw IOException("Error opening Tarfile");
 }
 
 Tarfile::~Tarfile()
 {
+    /* Close the tar file... */
     tar_append_eof(t);
 
     if (tar_close(t) != 0)
         throw IOException("Error closing Tarfile");
+
+    /* ...and wait for filter process to finish. */
+    int status;
+    waitpid(filter_pid, &status, 0);
+
+    if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+        throw IOException("Filter process error");
+    }
+
+    close(real_fd);
+}
+
+/* Launch a child process which can act as a filter (compress, encrypt, etc.)
+ * on the TAR output.  The file descriptor to which output should be written
+ * must be specified; the return value is the file descriptor which will be
+ * attached to the standard input of the filter program. */
+int Tarfile::spawn_filter(int fd_out)
+{
+    int fds[2];
+
+    /* Create a pipe for communicating with the filter process. */
+    if (pipe(fds) < 0) {
+        throw IOException("Unable to create pipe for filter");
+    }
+
+    /* Create a child process which can exec() the filter program. */
+    filter_pid = fork();
+    if (filter_pid < 0)
+        throw IOException("Unable to fork filter process");
+
+    if (filter_pid > 0) {
+        /* Parent process */
+        close(fds[0]);
+        cloexec(fds[1]);
+    } else {
+        /* Child process.  Rearrange file descriptors.  stdin is fds[0], stdout
+         * is fd_out, stderr is unchanged. */
+        close(fds[1]);
+
+        if (dup2(fds[0], 0) < 0)
+            exit(1);
+        close(fds[0]);
+
+        if (dup2(fd_out, 1) < 0)
+            exit(1);
+        close(fd_out);
+
+        /* Exec the filter program. */
+        execvp(filter_program[0], filter_program);
+
+        /* Should not reach here except for error cases. */
+        fprintf(stderr, "Could not exec filter: %m\n");
+        exit(1);
+    }
+
+    return fds[1];
 }
 
 void Tarfile::write_object(int id, const char *data, size_t len)
@@ -91,10 +168,27 @@ void Tarfile::internal_write_object(const string &path,
     size += blocks * T_BLOCKSIZE;
 }
 
+/* Estimate the size based on the size of the actual output file on disk.
+ * However, the filter may not have written all data yet, and in the event that
+ * it is buffering data to a large extent, also use */
+size_t Tarfile::size_estimate()
+{
+    struct stat statbuf;
+
+    if (fstat(real_fd, &statbuf) == 0) {
+        size_t disk_size = statbuf.st_size;
+
+        if (disk_size >= size / 128)
+            return disk_size;
+    }
+
+    return size;
+}
+
 static const size_t SEGMENT_SIZE = 4 * 1024 * 1024;
 
-string TarSegmentStore::write_object(const char *data, size_t len, const
-                                     std::string &group)
+ObjectReference TarSegmentStore::write_object(const char *data, size_t len,
+                                              const std::string &group)
 {
     struct segment_info *segment;
 
@@ -105,7 +199,7 @@ string TarSegmentStore::write_object(const char *data, size_t len, const
 
         segment->name = generate_uuid();
 
-        string filename = path + "/" + segment->name + ".tar";
+        string filename = path + "/" + segment->name + ".tar.bz2";
         segment->file = new Tarfile(filename, segment->name);
 
         segment->count = 0;
@@ -122,14 +216,14 @@ string TarSegmentStore::write_object(const char *data, size_t len, const
     segment->file->write_object(id, data, len);
     segment->count++;
 
-    string full_name = segment->name + "/" + id_buf;
+    ObjectReference ref(segment->name, id_buf);
 
     // If this segment meets or exceeds the size target, close it so that
     // future objects will go into a new segment.
     if (segment->file->size_estimate() >= SEGMENT_SIZE)
         close_segment(group);
 
-    return full_name;
+    return ref;
 }
 
 void TarSegmentStore::sync()
@@ -141,8 +235,6 @@ void TarSegmentStore::sync()
 void TarSegmentStore::close_segment(const string &group)
 {
     struct segment_info *segment = segments[group];
-    fprintf(stderr, "Closing segment group %s (%s)\n",
-            group.c_str(), segment->name.c_str());
 
     delete segment->file;
     segments.erase(segments.find(group));
@@ -168,8 +260,15 @@ void LbsObject::write(TarSegmentStore *store)
     assert(data != NULL);
     assert(!written);
 
-    name = store->write_object(data, data_len, group);
-
+    ref = store->write_object(data, data_len, group);
     written = true;
-    data = NULL;
+}
+
+void LbsObject::checksum()
+{
+    assert(written);
+
+    SHA1Checksum hash;
+    hash.process(data, data_len);
+    ref.set_checksum(hash.checksum_str());
 }