Am 23.06.20 um 19:47 schrieb SZEDER Gábor via GitGitGadget:
> From: =?UTF-8?q?SZEDER=20G=C3=A1bor?= <szeder.dev@xxxxxxxxx>
>
> In write_commit_graph_file() we now have one block of code filling the
> array of 'struct chunk_info' with the IDs and sizes of chunks to be
> written, and an other block of code calling the functions responsible
> for writing individual chunks. In case of optional chunks like Extra
> Edge List an Base Graphs List there is also a condition checking
> whether that chunk is necessary/desired, and that same condition is
> repeated in both blocks of code. Other, newer chunks have similar
> optional conditions.
>
> Eliminate these repeated conditions by storing the function pointers
> responsible for writing individual chunks in the 'struct chunk_info'
> array as well, and calling them in a loop to write the commit-graph
> file. This will open up the possibility for a bit of foolproofing in
> the following patch.
You can do that without storing function pointers by selecting the
function to use based on the chunk ID -- like parse_commit_graph() does
on the read side. Advantage: You don't need to press all write
functions into the same mold and can keep their individual signatures.
>
> Signed-off-by: SZEDER Gábor <szeder.dev@xxxxxxxxx>
> Signed-off-by: Derrick Stolee <dstolee@xxxxxxxxxxxxx>
> ---
> commit-graph.c | 31 +++++++++++++++++++------------
> 1 file changed, 19 insertions(+), 12 deletions(-)
>
> diff --git a/commit-graph.c b/commit-graph.c
> index f33bfe49b3..086fc2d070 100644
> --- a/commit-graph.c
> +++ b/commit-graph.c
> @@ -1555,9 +1555,13 @@ static int write_graph_chunk_base(struct hashfile *f,
> return 0;
> }
>
> +typedef int (*chunk_write_fn)(struct hashfile *f,
> + struct write_commit_graph_context *ctx);
> +
> struct chunk_info {
> uint32_t id;
> uint64_t size;
> + chunk_write_fn write_fn;
> };
>
> static int write_commit_graph_file(struct write_commit_graph_context *ctx)
> @@ -1615,27 +1619,34 @@ static int write_commit_graph_file(struct write_commit_graph_context *ctx)
>
> chunks[0].id = GRAPH_CHUNKID_OIDFANOUT;
> chunks[0].size = GRAPH_FANOUT_SIZE;
> + chunks[0].write_fn = write_graph_chunk_fanout;
> chunks[1].id = GRAPH_CHUNKID_OIDLOOKUP;
> chunks[1].size = hashsz * ctx->commits.nr;
> + chunks[1].write_fn = write_graph_chunk_oids;
> chunks[2].id = GRAPH_CHUNKID_DATA;
> chunks[2].size = (hashsz + 16) * ctx->commits.nr;
> + chunks[2].write_fn = write_graph_chunk_data;
> if (ctx->num_extra_edges) {
> chunks[num_chunks].id = GRAPH_CHUNKID_EXTRAEDGES;
> chunks[num_chunks].size = 4 * ctx->num_extra_edges;
> + chunks[num_chunks].write_fn = write_graph_chunk_extra_edges;
> num_chunks++;
> }
> if (ctx->changed_paths) {
> chunks[num_chunks].id = GRAPH_CHUNKID_BLOOMINDEXES;
> chunks[num_chunks].size = sizeof(uint32_t) * ctx->commits.nr;
> + chunks[num_chunks].write_fn = write_graph_chunk_bloom_indexes;
> num_chunks++;
> chunks[num_chunks].id = GRAPH_CHUNKID_BLOOMDATA;
> chunks[num_chunks].size = sizeof(uint32_t) * 3
> + ctx->total_bloom_filter_data_size;
> + chunks[num_chunks].write_fn = write_graph_chunk_bloom_data;
> num_chunks++;
> }
> if (ctx->num_commit_graphs_after > 1) {
> chunks[num_chunks].id = GRAPH_CHUNKID_BASE;
> chunks[num_chunks].size = hashsz * (ctx->num_commit_graphs_after - 1);
> + chunks[num_chunks].write_fn = write_graph_chunk_base;
> num_chunks++;
> }
>
> @@ -1671,19 +1682,15 @@ static int write_commit_graph_file(struct write_commit_graph_context *ctx)
> progress_title.buf,
> num_chunks * ctx->commits.nr);
> }
> - write_graph_chunk_fanout(f, ctx);
> - write_graph_chunk_oids(f, ctx);
> - write_graph_chunk_data(f, ctx);
> - if (ctx->num_extra_edges)
> - write_graph_chunk_extra_edges(f, ctx);
> - if (ctx->changed_paths) {
> - write_graph_chunk_bloom_indexes(f, ctx);
> - write_graph_chunk_bloom_data(f, ctx);
> - }
> - if (ctx->num_commit_graphs_after > 1 &&
> - write_graph_chunk_base(f, ctx)) {
> - return -1;
> +
> + for (i = 0; i < num_chunks; i++) {
> + if (chunks[i].write_fn(f, ctx)) {
> + error(_("failed writing chunk with id %"PRIx32""),
> + chunks[i].id);
Of all the write functions only write_graph_chunk_base() can return
non-zero and it already prints an error message in that case ("failed to
write correct number of base graph ids"). Why add this one?
> + return -1;
> + }
> }
> +
> stop_progress(&ctx->progress);
> strbuf_release(&progress_title);
>
>
