Added an option to explicitly give a SHA1 for the commit you want to restore.

ArqRestoreCommand.h

@@ -39,6 +39,7 @@
     NSString *encryptionPassword;
     S3Service *s3;
     NSString *path;
+    NSString *commitSHA1;
 }
 - (BOOL)readArgc:(int)argc argv:(const char **)argv;
 - (BOOL)execute:(NSError **)error;

ArqRestoreCommand.m

@@ -80,6 +80,7 @@
     [encryptionPassword release];
     [s3 release];
     [path release];
+    [commitSHA1 release];
     [super dealloc];
 }
 - (BOOL)readArgc:(int)argc argv:(const char **)argv {
@@ -98,6 +99,8 @@
             setHSLogLevel(hsLogLevelForName(level));
         } else if (path == nil) {
             path = [[NSString alloc] initWithUTF8String:argv[i]];
+        } else if (commitSHA1 == nil) {
+            commitSHA1 = [[NSString alloc] initWithUTF8String:argv[i]];
         } else {
             fprintf(stderr, "warning: ignoring argument '%s'\n", argv[i]);
         }
@@ -110,7 +113,7 @@
         ret = [self printArqFolders:error];
     } else {
         ret = [self restorePath:error];
-    }
+    }        
     return ret;
 }
 @end
@@ -219,7 +222,7 @@
         return NO;
     }
     
-    Restorer *restorer = [[[Restorer alloc] initWithRepo:repo bucketName:bucketName] autorelease];
+    Restorer *restorer = [[[Restorer alloc] initWithRepo:repo bucketName:bucketName commitSHA1:commitSHA1] autorelease];
     if (![restorer restore:error]) {
         return NO;
     }

Restorer.h

@@ -40,6 +40,7 @@
 @interface Restorer : NSObject {
     ArqRepo *repo;
     NSString *bucketName;
+    NSString *commitSHA1;
     NSString *rootPath;
     NSUInteger superUserNodeCount;
     NSMutableArray *restoreNodes;
@@ -51,10 +52,8 @@
     unsigned long long transferred;
     unsigned long long total;
 
-    BlobKey *headBlobKey;
+    Tree *rootTree;
-    Commit *head;
-    Tree *headTree;
 }
-- (id)initWithRepo:(ArqRepo *)theRepo bucketName:(NSString *)theBucketName;
+- (id)initWithRepo:(ArqRepo *)theRepo bucketName:(NSString *)theBucketName commitSHA1:(NSString *)theCommitSHA1;
 - (BOOL)restore:(NSError **)error;
 @end

Restorer.m

@@ -50,6 +50,8 @@
 #import "NSData-Gzip.h"
 #import "GunzipInputStream.h"
 #import "FileACL.h"
+#import "BlobKey.h"
+
 
 #define MAX_RETRIES (10)
 #define MY_BUF_SIZE (8192)
@@ -61,7 +63,6 @@
 - (BOOL)restoreNode:(Node *)theNode ofTree:(Tree *)theTree toPath:(NSString *)thePath error:(NSError **)error;
 - (BOOL)needSuperUserForTree:(Tree *)theTree;
 - (BOOL)needSuperUserForTree:(Tree *)theTree node:(Node *)theNode;
-- (BOOL)performSuperUserOps:(NSError **)error;
 - (BOOL)chownNode:(Node *)theNode ofTree:(Tree *)theTree atPath:(NSString *)thePath error:(NSError **)error;
 - (BOOL)chownTree:(Tree *)theTree atPath:(NSString *)thePath error:(NSError **)error;
 - (BOOL)applyUID:(int)theUID gid:(int)theGID mode:(int)theMode rdev:(int)theRdev toPath:(NSString *)thePath error:(NSError **)error;
@@ -77,10 +78,11 @@
 @end
 
 @implementation Restorer
-- (id)initWithRepo:(ArqRepo *)theArqRepo bucketName:(NSString *)theBucketName {
+- (id)initWithRepo:(ArqRepo *)theArqRepo bucketName:(NSString *)theBucketName commitSHA1:(NSString *)theCommitSHA1 {
     if (self = [super init]) {
         repo = [theArqRepo retain];
         bucketName = [theBucketName copy];
+        commitSHA1 = [theCommitSHA1 copy];
         rootPath = [[[[NSFileManager defaultManager] currentDirectoryPath] stringByAppendingPathComponent:theBucketName] copy];
         restoreNodes = [[NSMutableArray alloc] init];
         hardlinks = [[NSMutableDictionary alloc] init];
@@ -93,13 +95,12 @@
 - (void)dealloc {
     [repo release];
     [bucketName release];
+    [commitSHA1 release];
     [rootPath release];
     [restoreNodes release];
     [hardlinks release];
     [errorsByPath release];
-    [headBlobKey release];
+    [rootTree release];
-    [head release];
-    [headTree release];
     [super dealloc];
 }
 - (BOOL)restore:(NSError **)error {
@@ -111,20 +112,44 @@
         HSLogError(@"failed to create directory %@", rootPath);
         return NO;
     }
-    headBlobKey = [[repo headBlobKey:error] retain];
+    BlobKey *commitBlobKey = nil;
-    if (headBlobKey == nil) {
+    Commit *commit = nil;
-        SETNSERROR([Restorer errorDomain], -1, @"no backup found");
+    NSError *myError = nil;
+    if (commitSHA1 != nil) {
+        commitBlobKey = [[[BlobKey alloc] initWithSHA1:commitSHA1 stretchEncryptionKey:YES] autorelease];
+        commit = [repo commitForBlobKey:commitBlobKey error:&myError];
+        if (commit == nil) {
+            HSLogError(@"error attempting to read commit for %@", commitBlobKey);
+            
+            // Try without stretched encryption key.
+            commitBlobKey = [[[BlobKey alloc] initWithSHA1:commitSHA1 stretchEncryptionKey:NO] autorelease];
+            commit = [repo commitForBlobKey:commitBlobKey error:&myError];
+            if (commit == nil) {
+                HSLogError(@"error attempting to read commit for %@", commitBlobKey);
+                if (error != NULL) {
+                    *error = myError;
+                }
+                return NO;
+            }
+        }
+    } else {
+        commitBlobKey = [[repo headBlobKey:error] retain];
+        if (commitBlobKey == nil) {
+            SETNSERROR([Restorer errorDomain], -1, @"no backup found");
+            return NO;
+        }
+        commit = [repo commitForBlobKey:commitBlobKey error:error];
+        if (commit == nil) {
+            return NO;
+        }
+    }
+    printf("restoring %scommit %s\n", (commitSHA1 == nil ? "head " : ""), [[commitBlobKey description] UTF8String]);
+    
+    rootTree = [[repo treeForBlobKey:[commit treeBlobKey] error:error] retain];
+    if (rootTree == nil) {
         return NO;
     }
-    head = [[repo commitForBlobKey:headBlobKey error:error] retain];
+    if (![self restoreTree:rootTree toPath:rootPath error:error]) {
-    if (head == nil) {
-        return NO;
-    }
-    headTree = [[repo treeForBlobKey:[head treeBlobKey] error:error] retain];
-    if (headTree == nil) {
-        return NO;
-    }
-    if (![self restoreTree:headTree toPath:rootPath error:error]) {
         return NO;
     }
     return YES;
@@ -296,9 +321,6 @@
     }
     return NO;
 }
-- (BOOL)performSuperUserOps:(NSError **)error {
-    return [self chownTree:headTree atPath:rootPath error:error];
-}
 - (BOOL)chownNode:(Node *)theNode ofTree:(Tree *)theTree atPath:(NSString *)thePath error:(NSError **)error {
     if ([[errorsByPath allKeys] containsObject:thePath]) {
         HSLogDebug(@"error restoring %@; skipping chownNode", thePath);

arq_restore.m

@@ -39,6 +39,7 @@ static void printUsage(const char *exeName) {
 	fprintf(stderr, "Usage:\n");
     fprintf(stderr, "\t%s [-l log_level]\n", exeName);
     fprintf(stderr, "\t%s [-l log_level] /s3bucket/computerUUID/folderUUID\n", exeName);
+    fprintf(stderr, "\t%s [-l log_level] /s3bucket/computerUUID/folderUUID <commitSHA1>\n", exeName);
 }
 int main (int argc, const char **argv) {
     setHSLogLevel(HSLOG_LEVEL_WARN);

arq_restore.xcodeproj/project.pbxproj

@@ -51,6 +51,7 @@
 		F805B8C21160EC41007EC01E /* Security.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = F805B8C11160EC41007EC01E /* Security.framework */; };
 		F805B8CE1160ECD7007EC01E /* CoreServices.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = F805B8CD1160ECD7007EC01E /* CoreServices.framework */; };
 		F81426D714541A6C00D7E50A /* BackupSet.m in Sources */ = {isa = PBXBuildFile; fileRef = F81426D614541A6C00D7E50A /* BackupSet.m */; };
+		F8373E0F14794D01005AFBE6 /* ReflogEntry.m in Sources */ = {isa = PBXBuildFile; fileRef = F8373E0E14794D01005AFBE6 /* ReflogEntry.m */; };
 		F83C1A7411CA7C170001958F /* ArqRestoreCommand.m in Sources */ = {isa = PBXBuildFile; fileRef = F805B54C1160D3E6007EC01E /* ArqRestoreCommand.m */; };
 		F83C1A7711CA7C170001958F /* ArrayNode.m in Sources */ = {isa = PBXBuildFile; fileRef = F805B7421160DCFE007EC01E /* ArrayNode.m */; };
 		F83C1A7811CA7C170001958F /* BooleanNode.m in Sources */ = {isa = PBXBuildFile; fileRef = F805B7441160DCFE007EC01E /* BooleanNode.m */; };
@@ -339,6 +340,8 @@
 		F805B8CD1160ECD7007EC01E /* CoreServices.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = CoreServices.framework; path = System/Library/Frameworks/CoreServices.framework; sourceTree = SDKROOT; };
 		F81426D514541A6C00D7E50A /* BackupSet.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = BackupSet.h; sourceTree = "<group>"; };
 		F81426D614541A6C00D7E50A /* BackupSet.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = BackupSet.m; sourceTree = "<group>"; };
+		F8373E0D14794D01005AFBE6 /* ReflogEntry.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ReflogEntry.h; sourceTree = "<group>"; };
+		F8373E0E14794D01005AFBE6 /* ReflogEntry.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ReflogEntry.m; sourceTree = "<group>"; };
 		F83C1A5F11CA7A6B0001958F /* arq_verify.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = arq_verify.m; sourceTree = "<group>"; };
 		F83C1A6111CA7BD20001958F /* ArqVerifyCommand.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = ArqVerifyCommand.h; sourceTree = "<group>"; };
 		F83C1A6211CA7BD20001958F /* ArqVerifyCommand.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = ArqVerifyCommand.m; sourceTree = "<group>"; };
@@ -549,6 +552,8 @@
 				F89A1F3D13FAC6820071D321 /* UserLibrary_Arq.m */,
 				F81426D514541A6C00D7E50A /* BackupSet.h */,
 				F81426D614541A6C00D7E50A /* BackupSet.m */,
+				F8373E0D14794D01005AFBE6 /* ReflogEntry.h */,
+				F8373E0E14794D01005AFBE6 /* ReflogEntry.m */,
 			);
 			name = Source;
 			sourceTree = "<group>";
@@ -980,6 +985,7 @@
 				F89A205413FAE2DA0071D321 /* LocalS3Signer.m in Sources */,
 				F89A205A13FAE3010071D321 /* DataOutputStream.m in Sources */,
 				F81426D714541A6C00D7E50A /* BackupSet.m in Sources */,
+				F8373E0F14794D01005AFBE6 /* ReflogEntry.m in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};