reftable: rename scratch buffer

Both `struct block_writer` and `struct reftable_writer` have a `buf`
member that is being reused to optimize the number of allocations.
Rename the variable to `scratch` to clarify its intend and provide a
comment explaining why it exists.

Suggested-by: Christian Couder <christian.couder@gmail.com>
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/reftable/block.c b/reftable/block.c
index 1aa7e8cd3cbf0980f6bc20262be89e755d0a4b4b..01980784854cc454938bd2278b94047ff62c20d4 100644 (file)
--- a/reftable/block.c
+++ b/reftable/block.c
@@ -115,16 +115,16 @@ int block_writer_add(struct block_writer *w, struct reftable_record *rec)
        int n = 0;
        int err;
 
-       err = reftable_record_key(rec, &w->buf);
+       err = reftable_record_key(rec, &w->scratch);
        if (err < 0)
                goto done;
 
-       if (!w->buf.len) {
+       if (!w->scratch.len) {
                err = REFTABLE_API_ERROR;
                goto done;
        }
 
-       n = reftable_encode_key(&is_restart, out, last, w->buf,
+       n = reftable_encode_key(&is_restart, out, last, w->scratch,
                                reftable_record_val_type(rec));
        if (n < 0) {
                err = -1;
@@ -140,7 +140,7 @@ int block_writer_add(struct block_writer *w, struct reftable_record *rec)
        string_view_consume(&out, n);
 
        err = block_writer_register_restart(w, start.len - out.len, is_restart,
-                                           &w->buf);
+                                           &w->scratch);
 done:
        return err;
 }
@@ -565,7 +565,7 @@ void block_writer_release(struct block_writer *bw)
        REFTABLE_FREE_AND_NULL(bw->zstream);
        REFTABLE_FREE_AND_NULL(bw->restarts);
        REFTABLE_FREE_AND_NULL(bw->compressed);
-       reftable_buf_release(&bw->buf);
+       reftable_buf_release(&bw->scratch);
        reftable_buf_release(&bw->last_key);
        /* the block is not owned. */
 }

diff --git a/reftable/block.h b/reftable/block.h
index d76f00553073c10185e716e71e2f415ce5dcf7e2..0431e8591f41dedfb96eef304ea63ef2e9e5f5dd 100644 (file)
--- a/reftable/block.h
+++ b/reftable/block.h
@@ -39,7 +39,8 @@ struct block_writer {
        uint32_t restart_cap;
 
        struct reftable_buf last_key;
-       struct reftable_buf buf;
+       /* Scratch buffer used to avoid allocations. */
+       struct reftable_buf scratch;
        int entries;
 };
 

diff --git a/reftable/writer.c b/reftable/writer.c
index 6501376ce826469556a7dfa3c39258847300ae66..be0fae6cb229411258d40b8865c2fdee88fd5bcd 100644 (file)
--- a/reftable/writer.c
+++ b/reftable/writer.c
@@ -148,7 +148,7 @@ int reftable_writer_new(struct reftable_writer **out,
 
        reftable_buf_init(&wp->block_writer_data.last_key);
        reftable_buf_init(&wp->last_key);
-       reftable_buf_init(&wp->buf);
+       reftable_buf_init(&wp->scratch);
        REFTABLE_CALLOC_ARRAY(wp->block, opts.block_size);
        if (!wp->block) {
                reftable_free(wp);
@@ -181,7 +181,7 @@ static void writer_release(struct reftable_writer *w)
                w->block_writer = NULL;
                writer_clear_index(w);
                reftable_buf_release(&w->last_key);
-               reftable_buf_release(&w->buf);
+               reftable_buf_release(&w->scratch);
        }
 }
 
@@ -253,17 +253,17 @@ static int writer_add_record(struct reftable_writer *w,
 {
        int err;
 
-       err = reftable_record_key(rec, &w->buf);
+       err = reftable_record_key(rec, &w->scratch);
        if (err < 0)
                goto done;
 
-       if (reftable_buf_cmp(&w->last_key, &w->buf) >= 0) {
+       if (reftable_buf_cmp(&w->last_key, &w->scratch) >= 0) {
                err = REFTABLE_API_ERROR;
                goto done;
        }
 
        reftable_buf_reset(&w->last_key);
-       err = reftable_buf_add(&w->last_key, w->buf.buf, w->buf.len);
+       err = reftable_buf_add(&w->last_key, w->scratch.buf, w->scratch.len);
        if (err < 0)
                goto done;
 
@@ -339,25 +339,25 @@ int reftable_writer_add_ref(struct reftable_writer *w,
                goto out;
 
        if (!w->opts.skip_index_objects && reftable_ref_record_val1(ref)) {
-               reftable_buf_reset(&w->buf);
-               err = reftable_buf_add(&w->buf, (char *)reftable_ref_record_val1(ref),
+               reftable_buf_reset(&w->scratch);
+               err = reftable_buf_add(&w->scratch, (char *)reftable_ref_record_val1(ref),
                                       hash_size(w->opts.hash_id));
                if (err < 0)
                        goto out;
 
-               err = writer_index_hash(w, &w->buf);
+               err = writer_index_hash(w, &w->scratch);
                if (err < 0)
                        goto out;
        }
 
        if (!w->opts.skip_index_objects && reftable_ref_record_val2(ref)) {
-               reftable_buf_reset(&w->buf);
-               err = reftable_buf_add(&w->buf, reftable_ref_record_val2(ref),
+               reftable_buf_reset(&w->scratch);
+               err = reftable_buf_add(&w->scratch, reftable_ref_record_val2(ref),
                                       hash_size(w->opts.hash_id));
                if (err < 0)
                        goto out;
 
-               err = writer_index_hash(w, &w->buf);
+               err = writer_index_hash(w, &w->scratch);
                if (err < 0)
                        goto out;
        }

diff --git a/reftable/writer.h b/reftable/writer.h
index 421a897dccd85ad0532860ff1b4f38b2813d438d..1f4788a430c52c5387b5e97f639e84544d0b9ba2 100644 (file)
--- a/reftable/writer.h
+++ b/reftable/writer.h
@@ -20,7 +20,8 @@ struct reftable_writer {
        void *write_arg;
        int pending_padding;
        struct reftable_buf last_key;
-       struct reftable_buf buf;
+       /* Scratch buffer used to avoid allocations. */
+       struct reftable_buf scratch;
 
        /* offset of next block to write. */
        uint64_t next;