X-Git-Url: http://git.vrable.net/?a=blobdiff_plain;f=store.h;h=956a1b51b950c1759dbf75d38f305e794be3e3f2;hb=dbba40b5a3722e4acb0cc043f0be1bebff872f27;hp=a9d6365c4525e271e498275f6a4aa93397a499f3;hpb=08147fb0bc1d09610b05f3f7d54eda88ef5776ec;p=cumulus.git

diff --git a/store.h b/store.h
index a9d6365..956a1b5 100644
--- a/store.h
+++ b/store.h
@@ -3,14 +3,12 @@
  *
  * Backup data is stored in a collection of objects, which are grouped together
  * into segments for storage purposes.  This implementation of the object store
- * is built on top of libtar, and represents segments as TAR files and objects
- * as files within them. */
+ * represents segments as TAR files and objects as files within them. */
 
 #ifndef _LBS_STORE_H
 #define _LBS_STORE_H
 
 #include <stdint.h>
-#include <libtar.h>
 
 #include <list>
 #include <map>
@@ -19,7 +17,9 @@
 #include <iostream>
 #include <sstream>
 
+#include "localdb.h"
 #include "sha1.h"
+#include "ref.h"
 
 class LbsObject;
 
@@ -40,6 +40,30 @@ public:
     std::string getError() const { return error; }
 };
 
+/* Simplified TAR header--we only need to store regular files, don't need to
+ * handle long filenames, etc. */
+static const int TAR_BLOCK_SIZE = 512;
+
+struct tar_header
+{
+    char name[100];
+    char mode[8];
+    char uid[8];
+    char gid[8];
+    char size[12];
+    char mtime[12];
+    char chksum[8];
+    char typeflag;
+    char linkname[100];
+    char magic[8];
+    char uname[32];
+    char gname[32];
+    char devmajor[8];
+    char devminor[8];
+    char prefix[155];
+    char padding[12];
+};
+
 /* A simple wrapper around a single TAR file to represent a segment.  Objects
  * may only be written out all at once, since the tar header must be written
  * first; incremental writing is not supported. */
@@ -51,43 +75,53 @@ public:
     void write_object(int id, const char *data, size_t len);
 
     // Return an estimate of the size of the file.
-    size_t size_estimate() { return size; }
-
-    void internal_write_object(const std::string &path,
-                               const char *data, size_t len);
+    size_t size_estimate();
 
 private:
     size_t size;
     std::string segment_name;
-    TAR *t;
+
+    /* Filter support. */
+    int real_fd, filter_fd;
+    pid_t filter_pid;
+
+    // Write data to the tar file
+    void tar_write(const char *data, size_t size);
 };
 
 class TarSegmentStore {
 public:
     // New segments will be stored in the given directory.
-    TarSegmentStore(const std::string &path) { this->path = path; }
+    TarSegmentStore(const std::string &path,
+                    LocalDb *db = NULL)
+        { this->path = path; this->db = db; }
     ~TarSegmentStore() { sync(); }
 
     // Writes an object to segment in the store, and returns the name
     // (segment/object) to refer to it.  The optional parameter group can be
     // used to control object placement; objects with different group
     // parameters are kept in separate segments.
-    std::string write_object(const char *data, size_t len,
-                             const std::string &group = "");
+    ObjectReference write_object(const char *data, size_t len,
+                                 const std::string &group = "");
 
     // Ensure all segments have been fully written.
     void sync();
 
+    // Dump statistics to stdout about how much data has been written
+    void dump_stats();
+
 private:
     struct segment_info {
         Tarfile *file;
         std::string name;           // UUID
-        std::set<std::string> refs; // Other segments this one refers to
         int count;                  // Objects written to this segment
+        std::string basename;       // Name of segment without directory
+        std::string fullname;       // Full path to stored segment
     };
 
     std::string path;
     std::map<std::string, struct segment_info *> segments;
+    LocalDb *db;
 
     // Ensure that all segments in the given group have been fully written.
     void close_segment(const std::string &group);
@@ -114,17 +148,21 @@ public:
     // incrementally.  Data can be an arbitrary block of binary data of any
     // size.  The pointer to the data need only remain valid until write() is
     // called.
-    //const char *get_data() const { return data; }
-    //size_t get_data_len() const { return data_len; }
     void set_data(const char *d, size_t len) { data = d; data_len = len; }
 
     // Write an object to a segment, thus making it permanent.  This function
     // can be called at most once.
     void write(TarSegmentStore *store);
 
+    // Compute the checksum of an object, and include it in the object
+    // reference.  This should be called after write(), and the data specified
+    // by set_data() must remain valid through the call to checksum().
+    void checksum();
+
     // An object is assigned a permanent name once it has been written to a
     // segment.  Until that time, its name cannot be determined.
-    std::string get_name() const { return name; }
+    std::string get_name() const { return ref.to_string(); }
+    ObjectReference get_ref() { return ref; }
 
 private:
     std::string group;
@@ -132,9 +170,22 @@ private:
     size_t data_len;
 
     bool written;
-    std::string name;
-
-    std::set<std::string> refs;
+    ObjectReference ref;
 };
 
+/* Program through which segment data is piped before being written to file. */
+extern const char *filter_program;
+
+/* Extension which should be appended to segments written out (.tar is already
+ * included; this adds to it) */
+extern const char *filter_extension;
+
+/* Launch a process to filter data written to a file descriptor.  fd_out is the
+ * file descriptor where the filtered data should be written.  program is the
+ * filter program to execute (a single string which will be interpreted by
+ * /bin/sh).  The return value is a file descriptor to which the data to be
+ * filtered should be written.  The process ID of the filter process is stored
+ * at address filter_pid if non-NULL. */
+int spawn_filter(int fd_out, const char *program, pid_t *filter_pid);
+
 #endif // _LBS_STORE_H