git » summer » commit 7a34a0c

diff --git a/summer.go b/summer.go
index d7e04bc..e61df6e 100644
--- a/summer.go
+++ b/summer.go
@@ -20,14 +20,17 @@ Checksums are written to/read from each files' extended attributes by default,
 or to a separate database file (with the -db flag).
 
 Usage:
+
   summer update <dir>
       Verify checksums in the given directory, and update them for new or
       changed files.
   summer verify <dir>
       Verify checksums in the given directory.
   summer generate <dir>
-      Write checksums for the given directory. Pre-existing checksums are
-      overwritten without verification.
+      Write checksums for the given directory. Files with pre-existing
+      checksums are left untouched, and checksums are not verified.
+      Useful when generating checksums for a lot of files for the first time,
+      as is faster to resume work if interrupted.
   summer version
       Print software version information.
 
@@ -147,6 +150,15 @@ func generate(db DB, root string) error {
 		}
 		defer fd.Close()
 
+		hasAttr, err := db.Has(fd)
+		if err != nil {
+			return err
+		}
+		if hasAttr {
+			// Skip files that already have a checksum.
+			return nil
+		}
+
 		h := crc32.New(crc32c)
 		_, err = io.Copy(h, fd)
 		if err != nil {
diff --git a/test/basic.t b/test/basic.t
index b7abe63..dd65c48 100644
--- a/test/basic.t
+++ b/test/basic.t
@@ -57,11 +57,12 @@ it.
   detected 1 corrupted files
   [1]
 
-But "generate" does override it.
+Editing the file makes us ignore the previous checksum.
 
-  $ summer generate .
+  $ touch hola
+  $ summer update .
   \r (no-eol) (esc)
-  0s: 0 matched, 0 modified, 3 new, 0 corrupted
+  0s: 2 matched, 1 modified, 0 new, 0 corrupted
   $ summer verify .
   \r (no-eol) (esc)
   0s: 3 matched, 0 modified, 0 new, 0 corrupted
@@ -77,10 +78,7 @@ Check verbose and quiet.
   0s: 3 matched, 0 modified, 1 new, 0 corrupted
   $ summer -v generate .
   "denuevo": writing checksum \(checksum:\w+, mtime:\d+\) (re)
-  "empty": writing checksum \(checksum:0, mtime:\d+\) (re)
-  "hola": writing checksum \(checksum:\w+, mtime:\d+\) (re)
-  "nueva": writing checksum \(checksum:\w+, mtime:\d+\) (re)
-  0s: 0 matched, 0 modified, 4 new, 0 corrupted
+  0s: 0 matched, 0 modified, 1 new, 0 corrupted
   $ summer -q verify .
   $ summer -q generate .
   $ summer -q update .
diff --git a/test/help.t b/test/help.t
index beaefd4..a14fefa 100644
--- a/test/help.t
+++ b/test/help.t
@@ -14,14 +14,17 @@ No arguments.
   or to a separate database file (with the -db flag).
   
   Usage:
+  
     summer update <dir>
         Verify checksums in the given directory, and update them for new or
         changed files.
     summer verify <dir>
         Verify checksums in the given directory.
     summer generate <dir>
-        Write checksums for the given directory. Pre-existing checksums are
-        overwritten without verification.
+        Write checksums for the given directory. Files with pre-existing
+        checksums are left untouched, and checksums are not verified.
+        Useful when generating checksums for a lot of files for the first time,
+        as is faster to resume work if interrupted.
     summer version
         Print software version information.
   
@@ -47,14 +50,17 @@ Too few arguments.
   or to a separate database file (with the -db flag).
   
   Usage:
+  
     summer update <dir>
         Verify checksums in the given directory, and update them for new or
         changed files.
     summer verify <dir>
         Verify checksums in the given directory.
     summer generate <dir>
-        Write checksums for the given directory. Pre-existing checksums are
-        overwritten without verification.
+        Write checksums for the given directory. Files with pre-existing
+        checksums are left untouched, and checksums are not verified.
+        Useful when generating checksums for a lot of files for the first time,
+        as is faster to resume work if interrupted.
     summer version
         Print software version information.
   
@@ -80,14 +86,17 @@ No valid path (the argument is given, but it is empty).
   or to a separate database file (with the -db flag).
   
   Usage:
+  
     summer update <dir>
         Verify checksums in the given directory, and update them for new or
         changed files.
     summer verify <dir>
         Verify checksums in the given directory.
     summer generate <dir>
-        Write checksums for the given directory. Pre-existing checksums are
-        overwritten without verification.
+        Write checksums for the given directory. Files with pre-existing
+        checksums are left untouched, and checksums are not verified.
+        Useful when generating checksums for a lot of files for the first time,
+        as is faster to resume work if interrupted.
     summer version
         Print software version information.
   
diff --git a/test/sqlite.t b/test/sqlite.t
index 35db2b5..056f317 100644
--- a/test/sqlite.t
+++ b/test/sqlite.t
@@ -26,9 +26,9 @@ Check that the root path doesn't confuse us.
 
 Force a write error to check it is appropriately handled.
 
-  $ summer "-db=file:db.sqlite3?mode=ro" generate .
+  $ summer "-db=file:db.sqlite3?mode=ro" update .
   \r (no-eol) (esc)
-  0s: 0 matched, 0 modified, 0 new, 0 corrupted
+  0s: 0 matched, 1 modified, 0 new, 0 corrupted
   attempt to write a readonly database
   [1]