fs-compress: Support reading uncompressed input by prefixing compression format with...

diff --git a/src/plugins/fs-compress/fs-compress.c b/src/plugins/fs-compress/fs-compress.c
index eecbe0f63df3cc2614cdcee637944a0f700c5102..462275291d41437def86709f2df7d3805fd8b086 100644 (file)
--- a/src/plugins/fs-compress/fs-compress.c
+++ b/src/plugins/fs-compress/fs-compress.c
@@ -3,6 +3,8 @@
 #include "lib.h"
 #include "array.h"
 #include "istream.h"
+#include "istream-tee.h"
+#include "istream-try.h"
 #include "ostream.h"
 #include "iostream-temp.h"
 #include "compression.h"
@@ -12,6 +14,7 @@ struct compress_fs {
        struct fs fs;
        const struct compression_handler *handler;
        unsigned int compress_level;
+       bool try_plain;
 };
 
 struct compress_fs_file {
@@ -45,6 +48,11 @@ fs_compress_init(struct fs *_fs, const char *args, const
        const char *parent_name, *parent_args;
 
        /* get compression handler name */
+       if (strncmp(args, "maybe-", 6) == 0) {
+               fs->try_plain = TRUE;
+               args += 6;
+       }
+
        p = strchr(args, ':');
        if (p == NULL) {
                fs_set_error(_fs, "Compression method not given as parameter");
@@ -150,6 +158,29 @@ static void fs_compress_file_close(struct fs_file *_file)
                fs_file_close(_file->parent);
 }
 
+static struct istream *
+fs_compress_try_create_stream(struct compress_fs_file *file,
+                             struct istream *plain_input)
+{
+       struct tee_istream *tee_input;
+       struct istream *child_input, *ret_input, *try_inputs[3];
+
+       if (!file->fs->try_plain)
+               return file->fs->handler->create_istream(plain_input, FALSE);
+
+       tee_input = tee_i_stream_create(plain_input);
+       child_input = tee_i_stream_create_child(tee_input);
+       try_inputs[0] = file->fs->handler->create_istream(child_input, FALSE);
+       try_inputs[1] = tee_i_stream_create_child(tee_input);
+       try_inputs[2] = NULL;
+       i_stream_unref(&child_input);
+
+       ret_input = istream_try_create(try_inputs);
+       i_stream_unref(&try_inputs[0]);
+       i_stream_unref(&try_inputs[1]);
+       return ret_input;
+}
+
 static struct istream *
 fs_compress_read_stream(struct fs_file *_file, size_t max_buffer_size)
 {
@@ -163,7 +194,8 @@ fs_compress_read_stream(struct fs_file *_file, size_t max_buffer_size)
        }
 
        input = fs_read_stream(file->super_read, max_buffer_size);
-       file->input = file->fs->handler->create_istream(input, FALSE);
+       file->input = fs_compress_try_create_stream(file, input);
+
        i_stream_unref(&input);
        i_stream_ref(file->input);
        return file->input;