Skip to content

Improve Zstd.decompress performance by avoiding unnecessary memory copy #127

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
SpringMT merged 1 commit into from
Dec 26, 2025
+1 −6
Merged

Improve Zstd.decompress performance by avoiding unnecessary memory copy #127

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 1 addition & 6 deletions ext/zstdruby/zstdruby.c
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -78,9 +78,7 @@ static VALUE rb_decompress(int argc, VALUE *argv, VALUE self)
StringValue(input_value);

size_t in_size = RSTRING_LEN(input_value);
const unsigned char *in_r = (const unsigned char *)RSTRING_PTR(input_value);
unsigned char *in = ALLOC_N(unsigned char, in_size);
memcpy(in, in_r, in_size);
const unsigned char *in = (const unsigned char *)RSTRING_PTR(input_value);

size_t off = 0;
const uint32_t ZSTD_MAGIC = 0xFD2FB528U;
Expand All @@ -107,22 +105,19 @@ static VALUE rb_decompress(int argc, VALUE *argv, VALUE self)
if (magic == ZSTD_MAGIC) {
ZSTD_DCtx *dctx = ZSTD_createDCtx();
if (!dctx) {
xfree(in);
rb_raise(rb_eRuntimeError, "ZSTD_createDCtx failed");
}

VALUE out = decode_one_frame(dctx, in + off, in_size - off, kwargs);

ZSTD_freeDCtx(dctx);
xfree(in);
RB_GC_GUARD(input_value);
return out;
}

off += 1;
}

xfree(in);
RB_GC_GUARD(input_value);
rb_raise(rb_eRuntimeError, "not a zstd frame (magic not found)");
}
Expand Down