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Merged
taylordotfish merged 1 commit into from
Sep 27, 2025
Merged

Make bun.webcore.Blob smaller and ref-counted #23015

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1 change: 0 additions & 1 deletion src/StandaloneModuleGraph.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -199,7 +199,6 @@ pub const StandaloneModuleGraph = struct {
store.ref();

const b = bun.webcore.Blob.initWithStore(store, globalObject).new();
b.allocator = bun.default_allocator;

if (bun.http.MimeType.byExtensionNoDefault(bun.strings.trimLeadingChar(std.fs.path.extension(this.name), '.'))) |mime| {
store.mime_type = mime;
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15 changes: 4 additions & 11 deletions src/ast/Macro.zig
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Expand Up @@ -325,7 +325,7 @@ pub const Runner = struct {
return _entry.value_ptr.*;
}

var blob_: ?jsc.WebCore.Blob = null;
var blob_: ?*const jsc.WebCore.Blob = null;
const mime_type: ?MimeType = null;

if (value.jsType() == .DOMWrapper) {
Expand All @@ -334,30 +334,23 @@ pub const Runner = struct {
} else if (value.as(jsc.WebCore.Request)) |resp| {
return this.run(try resp.getBlobWithoutCallFrame(this.global));
} else if (value.as(jsc.WebCore.Blob)) |resp| {
blob_ = resp.*;
blob_.?.allocator = null;
blob_ = resp;
} else if (value.as(bun.api.ResolveMessage) != null or value.as(bun.api.BuildMessage) != null) {
_ = this.macro.vm.uncaughtException(this.global, value, false);
return error.MacroFailed;
}
}

if (blob_) |*blob| {
const out_expr = Expr.fromBlob(
if (blob_) |blob| {
return Expr.fromBlob(
blob,
this.allocator,
mime_type,
this.log,
this.caller.loc,
) catch {
blob.deinit();
return error.MacroFailed;
};
if (out_expr.data == .e_string) {
blob.deinit();
}

return out_expr;
}

return Expr.init(E.String, E.String.empty, this.caller.loc);
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4 changes: 0 additions & 4 deletions src/bun.js/api/BunObject.zig
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Original file line number Diff line number Diff line change
Expand Up @@ -1337,7 +1337,6 @@ pub fn getEmbeddedFiles(globalThis: *jsc.JSGlobalObject, _: *jsc.JSObject) bun.J
// We call .dupe() on this to ensure that we don't return a blob that might get freed later.
const input_blob = file.blob(globalThis);
const blob = jsc.WebCore.Blob.new(input_blob.dupeWithContentType(true));
blob.allocator = bun.default_allocator;
blob.name = input_blob.name.dupeRef();
try array.putIndex(globalThis, i, blob.toJS(globalThis));
i += 1;
Expand Down Expand Up @@ -2048,7 +2047,6 @@ pub fn createBunStdin(globalThis: *jsc.JSGlobalObject) callconv(.C) jsc.JSValue
var blob = jsc.WebCore.Blob.new(
jsc.WebCore.Blob.initWithStore(store, globalThis),
);
blob.allocator = bun.default_allocator;
return blob.toJS(globalThis);
}

Expand All @@ -2059,7 +2057,6 @@ pub fn createBunStderr(globalThis: *jsc.JSGlobalObject) callconv(.C) jsc.JSValue
var blob = jsc.WebCore.Blob.new(
jsc.WebCore.Blob.initWithStore(store, globalThis),
);
blob.allocator = bun.default_allocator;
return blob.toJS(globalThis);
}

Expand All @@ -2070,7 +2067,6 @@ pub fn createBunStdout(globalThis: *jsc.JSGlobalObject) callconv(.C) jsc.JSValue
var blob = jsc.WebCore.Blob.new(
jsc.WebCore.Blob.initWithStore(store, globalThis),
);
blob.allocator = bun.default_allocator;
return blob.toJS(globalThis);
}

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4 changes: 2 additions & 2 deletions src/bun.js/api/server/FileRoute.zig
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Expand Up @@ -68,7 +68,7 @@ pub fn fromJS(globalThis: *jsc.JSGlobalObject, argument: jsc.JSValue) bun.JSErro
var blob = response.body.value.use();

blob.globalThis = globalThis;
blob.allocator = null;
bun.assertf(!blob.isHeapAllocated(), "expected blob not to be heap-allocated", .{});
response.body.value = .{ .Blob = blob.dupe() };
const headers = bun.handleOom(Headers.from(response.init.headers, bun.default_allocator, .{ .body = &.{ .Blob = blob } }));
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taylordotfish marked this conversation as resolved.

Expand All @@ -87,7 +87,7 @@ pub fn fromJS(globalThis: *jsc.JSGlobalObject, argument: jsc.JSValue) bun.JSErro
if (blob.needsToReadFile()) {
var b = blob.dupe();
b.globalThis = globalThis;
b.allocator = null;
bun.assertf(!b.isHeapAllocated(), "expected blob not to be heap-allocated", .{});
return bun.new(FileRoute, .{
.ref_count = .init(),
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taylordotfish marked this conversation as resolved.
.server = null,
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6 changes: 5 additions & 1 deletion src/bun.js/api/server/StaticRoute.zig
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Expand Up @@ -113,7 +113,11 @@ pub fn fromJS(globalThis: *jsc.JSGlobalObject, argument: jsc.JSValue) bun.JSErro
}
var blob = response.body.value.use();
blob.globalThis = globalThis;
blob.allocator = null;
bun.assertf(
!blob.isHeapAllocated(),
"expected blob not to be heap-allocated",
.{},
);
response.body.value = .{ .Blob = blob.dupe() };
Comment thread
taylordotfish marked this conversation as resolved.

break :brk .{ .Blob = blob };
Expand Down
6 changes: 3 additions & 3 deletions src/bun.js/bindings/blob.cpp
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Expand Up @@ -2,14 +2,14 @@
#include "ZigGeneratedClasses.h"

extern "C" JSC::EncodedJSValue SYSV_ABI Blob__create(JSC::JSGlobalObject* globalObject, void* impl);
extern "C" void* Blob__setAsFile(void* impl, BunString* filename);
extern "C" void Blob__setAsFile(void* impl, BunString* filename);

namespace WebCore {

JSC::JSValue toJS(JSC::JSGlobalObject* lexicalGlobalObject, JSDOMGlobalObject* globalObject, WebCore::Blob& impl)
{
BunString filename = Bun::toString(impl.fileName());
impl.m_impl = Blob__setAsFile(impl.impl(), &filename);
Blob__setAsFile(impl.impl(), &filename);

return JSC::JSValue::decode(Blob__create(lexicalGlobalObject, Blob__dupe(impl.impl())));
}
Expand All @@ -28,7 +28,7 @@ JSC::JSValue toJSNewlyCreated(JSC::JSGlobalObject* lexicalGlobalObject, JSDOMGlo

size_t Blob::memoryCost() const
{
return sizeof(Blob) + JSBlob::memoryCost(m_impl);
return sizeof(Blob) + JSBlob::memoryCost(impl());
}

}
68 changes: 46 additions & 22 deletions src/bun.js/bindings/blob.h
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Expand Up @@ -8,44 +8,60 @@ namespace WebCore {

extern "C" void* Blob__dupeFromJS(JSC::EncodedJSValue impl);
extern "C" void* Blob__dupe(void* impl);
extern "C" void Blob__destroy(void* impl);
extern "C" void* Blob__getDataPtr(JSC::EncodedJSValue blob);
extern "C" size_t Blob__getSize(JSC::EncodedJSValue blob);
extern "C" void* Blob__fromBytes(JSC::JSGlobalObject* globalThis, const void* ptr, size_t len);
extern "C" void* Blob__ref(void* impl);
extern "C" void* Blob__deref(void* impl);

class Blob : public RefCounted<Blob> {
public:
void* impl()
// Opaque type corresponding to `bun.webcore.Blob`.
class BlobImpl;

struct BlobImplRefDerefTraits {
static ALWAYS_INLINE BlobImpl* refIfNotNull(BlobImpl* ptr)
{
return m_impl;
if (ptr) [[likely]]
Blob__ref(ptr);
return ptr;
}

static RefPtr<Blob> create(JSC::JSValue impl)
static ALWAYS_INLINE BlobImpl& ref(BlobImpl& ref)
{
void* implPtr = Blob__dupeFromJS(JSValue::encode(impl));
if (!implPtr)
return nullptr;
Blob__ref(&ref);
return ref;
}

return adoptRef(*new Blob(implPtr));
static ALWAYS_INLINE void derefIfNotNull(BlobImpl* ptr)
{
if (ptr) [[likely]]
Blob__deref(ptr);
}
};

static RefPtr<Blob> create(std::span<const uint8_t> bytes, JSC::JSGlobalObject* globalThis)
using BlobRef = Ref<BlobImpl, RawPtrTraits<BlobImpl>, BlobImplRefDerefTraits>;
using BlobRefPtr = RefPtr<BlobImpl, RawPtrTraits<BlobImpl>, BlobImplRefDerefTraits>;

// TODO: Now that `bun.webcore.Blob` is ref-counted, can `RefPtr<Blob>` be replaced with `Blob`?
class Blob : public RefCounted<Blob> {
public:
BlobImpl* impl() const
{
return adoptRef(*new Blob(Blob__fromBytes(globalThis, bytes.data(), bytes.size())));
return m_impl.get();
}

static RefPtr<Blob> create(void* ptr)
static RefPtr<Blob> create(JSC::JSValue impl)
{
void* implPtr = Blob__dupe(ptr);
if (!implPtr)
return nullptr;
return createAdopted(Blob__dupeFromJS(JSValue::encode(impl)));
}

return adoptRef(*new Blob(implPtr));
static RefPtr<Blob> create(std::span<const uint8_t> bytes, JSC::JSGlobalObject* globalThis)
{
return createAdopted(Blob__fromBytes(globalThis, bytes.data(), bytes.size()));
}

~Blob()
static RefPtr<Blob> create(void* ptr)
{
Blob__destroy(m_impl);
return createAdopted(Blob__dupe(ptr));
}

String fileName()
Expand All @@ -57,17 +73,25 @@ class Blob : public RefCounted<Blob> {
{
m_fileName = fileName;
}
void* m_impl;

size_t memoryCost() const;

private:
Blob(void* impl, String fileName = String())
: m_impl(adoptRef<BlobImpl, RawPtrTraits<BlobImpl>, BlobImplRefDerefTraits>(
static_cast<BlobImpl*>(impl)))
, m_fileName(std::move(fileName))
{
m_impl = impl;
m_fileName = fileName;
}

static RefPtr<Blob> createAdopted(void* ptr)
{
if (!ptr)
return nullptr;
return adoptRef(new Blob(ptr));
}

BlobRefPtr m_impl;
String m_fileName;
};

Expand Down
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