http2: shrink memory to match read data

Perform a shrinking `Realloc()` so that less data is
used for HTTP2 reads.

PR-URL: https://github.com/nodejs/node/pull/26201
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
This commit is contained in:
Anna Henningsen 2019-02-19 14:25:03 +01:00
parent e51da1fcad
commit 83e1b97443
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2 changed files with 17 additions and 20 deletions

View File

@ -1774,17 +1774,8 @@ void Http2Session::OnStreamRead(ssize_t nread, const uv_buf_t& buf) {
Http2Scope h2scope(this);
CHECK_NOT_NULL(stream_);
Debug(this, "receiving %d bytes", nread);
IncrementCurrentSessionMemory(buf.len);
CHECK(stream_buf_ab_.IsEmpty());
OnScopeLeave on_scope_leave([&]() {
// Once finished handling this write, reset the stream buffer.
// The memory has either been free()d or was handed over to V8.
DecrementCurrentSessionMemory(buf.len);
stream_buf_ab_ = Local<ArrayBuffer>();
stream_buf_ = uv_buf_init(nullptr, 0);
});
// Only pass data on if nread > 0
if (nread <= 0) {
free(buf.base);
@ -1794,19 +1785,25 @@ void Http2Session::OnStreamRead(ssize_t nread, const uv_buf_t& buf) {
return;
}
// Shrink to the actual amount of used data.
char* base = Realloc(buf.base, nread);
IncrementCurrentSessionMemory(nread);
OnScopeLeave on_scope_leave([&]() {
// Once finished handling this write, reset the stream buffer.
// The memory has either been free()d or was handed over to V8.
DecrementCurrentSessionMemory(nread);
stream_buf_ab_ = Local<ArrayBuffer>();
stream_buf_ = uv_buf_init(nullptr, 0);
});
// Make sure that there was no read previously active.
CHECK_NULL(stream_buf_.base);
CHECK_EQ(stream_buf_.len, 0);
// Remember the current buffer, so that OnDataChunkReceived knows the
// offset of a DATA frame's data into the socket read buffer.
stream_buf_ = uv_buf_init(buf.base, nread);
// Verify that currently: There is memory allocated into which
// the data has been read, and that memory buffer is at least as large
// as the amount of data we have read, but we have not yet made an
// ArrayBuffer out of it.
CHECK_LE(static_cast<size_t>(nread), stream_buf_.len);
stream_buf_ = uv_buf_init(base, nread);
Isolate* isolate = env()->isolate();
@ -1814,9 +1811,9 @@ void Http2Session::OnStreamRead(ssize_t nread, const uv_buf_t& buf) {
// as slices of this array buffer to avoid having to copy memory.
stream_buf_ab_ =
ArrayBuffer::New(isolate,
buf.base,
nread,
ArrayBufferCreationMode::kInternalized);
base,
nread,
ArrayBufferCreationMode::kInternalized);
statistics_.data_received += nread;
ssize_t ret = Write(&stream_buf_, 1);

View File

@ -8,7 +8,7 @@ const http2 = require('http2');
// Test that maxSessionMemory Caps work
const largeBuffer = Buffer.alloc(1e6);
const largeBuffer = Buffer.alloc(2e6);
const server = http2.createServer({ maxSessionMemory: 1 });