Polish the streambuffer API a bit

This commit is contained in:
2021-07-19 17:32:24 -04:00
parent f8f8a9843f
commit 08ca274444
5 changed files with 303 additions and 195 deletions

View File

@@ -84,7 +84,7 @@ int64_t IdGlobalPool::alloc_id_for_thread(lua_State *L) {
void IdGlobalPool::serialize(StreamBuffer *sb) {
sb->write_int64(next_batch_);
sb->write_int64(next_id_);
sb->write_size(salvaged_.size());
sb->write_uint32(salvaged_.size());
for (int64_t batch : salvaged_) {
sb->write_int64(batch);
}
@@ -93,7 +93,7 @@ void IdGlobalPool::serialize(StreamBuffer *sb) {
void IdGlobalPool::deserialize(StreamBuffer *sb) {
next_batch_ = sb->read_int64();
next_id_ = sb->read_int64();
size_t salvaged_size = sb->read_size();
uint32_t salvaged_size = sb->read_uint32();
salvaged_.resize(salvaged_size);
for (int i=0; i < int(salvaged_size); i++) {
salvaged_[i] = sb->read_int64();

View File

@@ -26,7 +26,7 @@ SchedEntry Schedule::pop() {
}
void Schedule::serialize(StreamBuffer *sb) {
sb->write_size(schedule_.size());
sb->write_uint32(schedule_.size());
for (const SchedEntry &entry : schedule_) {
sb->write_int64(entry.clock_);
sb->write_int64(entry.thread_id_);
@@ -36,7 +36,7 @@ void Schedule::serialize(StreamBuffer *sb) {
void Schedule::deserialize(StreamBuffer *sb) {
schedule_.clear();
size_t nentry = sb->read_size();
size_t nentry = sb->read_uint32();
for (size_t i = 0; i < nentry; i++) {
int64_t clock = sb->read_int64();
int64_t thread_id = sb->read_int64();

View File

@@ -103,38 +103,115 @@ void StreamBuffer::clear() {
lua_reader_size_ = 0;
}
char *StreamBuffer::alloc_space(int64_t bytes) {
assert(bytes >= 0);
make_space(bytes);
return write_cursor_;
// These routines return true if you can losslessly cast the
// specified value to the specified type.
static inline bool safe_to_cast_to_int8(int64_t vv) {
return ((vv + 0x80LL) & 0xFFFFFFFFFFFFFF00LL) == 0;
}
void StreamBuffer::wrote_space(int64_t bytes) {
int64_t maxbuf = buf_hi_ - write_cursor_;
assert(bytes >= 0);
assert(bytes <= maxbuf);
write_cursor_ += bytes;
static inline bool safe_to_cast_to_int16(int64_t vv) {
return ((vv + 0x8000LL) & 0xFFFFFFFFFFFF0000LL) == 0;
}
void StreamBuffer::write_int8(int8_t v) {
static inline bool safe_to_cast_to_int32(int64_t vv) {
return ((vv + 0x80000000LL) & 0xFFFFFFFF00000000LL) == 0;
}
static inline bool safe_to_cast_to_int64(int64_t vv) {
return true;
}
static inline bool safe_to_cast_to_uint8(uint64_t vv) {
return (vv & 0xFFFFFFFFFFFFFF00LL) == 0;
}
static inline bool safe_to_cast_to_uint16(uint64_t vv) {
return (vv & 0xFFFFFFFFFFFF0000LL) == 0;
}
static inline bool safe_to_cast_to_uint32(uint64_t vv) {
return (vv & 0xFFFFFFFF00000000LL) == 0;
}
static inline bool safe_to_cast_to_uint64(uint64_t vv) {
return true;
}
void StreamBuffer::write_bytes(const char *s, int64_t len) {
make_space(len);
memcpy(write_cursor_, s, len);
write_cursor_ += len;
}
const char *StreamBuffer::read_bytes(int64_t bytes) {
check_available(bytes);
char *data = read_cursor_;
read_cursor_ += bytes;
return data;
}
void StreamBuffer::write_int8(int64_t vv) {
assert(safe_to_cast_to_int8(vv));
int8_t v = vv;
make_space(1);
memcpy(write_cursor_, &v, 1);
write_cursor_ += 1;
}
void StreamBuffer::write_int16(int16_t v) {
void StreamBuffer::write_int16(int64_t vv) {
assert(safe_to_cast_to_int16(vv));
int16_t v = vv;
make_space(2);
memcpy(write_cursor_, &v, 2);
write_cursor_ += 2;
}
void StreamBuffer::write_int32(int32_t v) {
void StreamBuffer::write_int32(int64_t vv) {
assert(safe_to_cast_to_int32(vv));
int32_t v = vv;
make_space(4);
memcpy(write_cursor_, &v, 4);
write_cursor_ += 4;
}
void StreamBuffer::write_int64(int64_t v) {
void StreamBuffer::write_int64(int64_t vv) {
assert(safe_to_cast_to_int64(vv));
int64_t v = vv;
make_space(8);
memcpy(write_cursor_, &v, 8);
write_cursor_ += 8;
}
void StreamBuffer::write_uint8(uint64_t vv) {
assert(safe_to_cast_to_uint8(vv));
uint8_t v = vv;
make_space(1);
memcpy(write_cursor_, &v, 1);
write_cursor_ += 1;
}
void StreamBuffer::write_uint16(uint64_t vv) {
assert(safe_to_cast_to_uint16(vv));
uint16_t v = vv;
make_space(2);
memcpy(write_cursor_, &v, 2);
write_cursor_ += 2;
}
void StreamBuffer::write_uint32(uint64_t vv) {
assert(safe_to_cast_to_uint32(vv));
uint32_t v = vv;
make_space(4);
memcpy(write_cursor_, &v, 4);
write_cursor_ += 4;
}
void StreamBuffer::write_uint64(uint64_t vv) {
assert(safe_to_cast_to_uint64(vv));
uint64_t v = vv;
make_space(8);
memcpy(write_cursor_, &v, 8);
write_cursor_ += 8;
@@ -152,53 +229,6 @@ void StreamBuffer::write_double(double d) {
write_cursor_ += 8;
}
void StreamBuffer::write_hashvalue(const util::HashValue &hv) {
make_space(16);
memcpy(write_cursor_, &hv, 16);
write_cursor_ += 16;
}
void StreamBuffer::write_bytes(const char *s, int64_t len) {
make_space(len);
memcpy(write_cursor_, s, len);
write_cursor_ += len;
}
void StreamBuffer::write_ztbytes(const char *s) {
write_bytes(s, strlen(s));
}
void StreamBuffer::write_string(const std::string &s) {
if (s.size() >= 255) {
write_uint8(0xFF);
write_uint64(s.size());
write_bytes(s.c_str(), s.size());
} else {
write_uint8(s.size());
write_bytes(s.c_str(), s.size());
}
}
void StreamBuffer::overwrite_int8(int64_t write_count_after, int8_t v) {
char *target = get_overwrite(1, write_count_after);
memcpy(target, &v, 1);
}
void StreamBuffer::overwrite_int16(int64_t write_count_after, int16_t v) {
char *target = get_overwrite(2, write_count_after);
memcpy(target, &v, 2);
}
void StreamBuffer::overwrite_int32(int64_t write_count_after, int32_t v) {
char *target = get_overwrite(4, write_count_after);
memcpy(target, &v, 4);
}
void StreamBuffer::overwrite_int64(int64_t write_count_after, int64_t v) {
char *target = get_overwrite(8, write_count_after);
memcpy(target, &v, 8);
}
int8_t StreamBuffer::read_int8() {
check_available(1);
int8_t v;
@@ -231,14 +261,6 @@ int64_t StreamBuffer::read_int64() {
return v;
}
util::HashValue StreamBuffer::read_hashvalue() {
check_available(16);
util::HashValue hv;
memcpy(&hv, read_cursor_, 16);
read_cursor_ += 16;
return hv;
}
float StreamBuffer::read_float() {
check_available(4);
float f;
@@ -255,23 +277,29 @@ double StreamBuffer::read_double() {
return d;
}
size_t StreamBuffer::read_size() {
return read_size_limit(0xFFFFFFF);
void StreamBuffer::write_hashvalue(const util::HashValue &hv) {
make_space(16);
memcpy(write_cursor_, &hv, 16);
write_cursor_ += 16;
}
size_t StreamBuffer::read_size_limit(size_t limit) {
int64_t value = read_int64();
if ((value < 0)||(value > int64_t(limit))) {
throw StreamCorruption();
void StreamBuffer::write_string(const std::string &s) {
if (s.size() >= 255) {
write_uint8(0xFF);
write_uint64(s.size());
write_bytes(s.c_str(), s.size());
} else {
write_uint8(s.size());
write_bytes(s.c_str(), s.size());
}
return size_t(value);
}
const char *StreamBuffer::read_bytes(int64_t bytes) {
check_available(bytes);
char *data = read_cursor_;
read_cursor_ += bytes;
return data;
util::HashValue StreamBuffer::read_hashvalue() {
check_available(16);
util::HashValue hv;
memcpy(&hv, read_cursor_, 16);
read_cursor_ += 16;
return hv;
}
std::string StreamBuffer::read_string() {
@@ -289,6 +317,63 @@ std::string StreamBuffer::read_string_limit(int64_t max_allowed) {
return std::string(bytes, len);
}
void StreamBuffer::overwrite_int8(int64_t write_count_after, int64_t vv) {
assert(safe_to_cast_to_int8(vv));
int8_t v = vv;
char *target = get_overwrite(1, write_count_after);
memcpy(target, &v, 1);
}
void StreamBuffer::overwrite_int16(int64_t write_count_after, int64_t vv) {
assert(safe_to_cast_to_int16(vv));
int16_t v = vv;
char *target = get_overwrite(2, write_count_after);
memcpy(target, &v, 2);
}
void StreamBuffer::overwrite_int32(int64_t write_count_after, int64_t vv) {
assert(safe_to_cast_to_int32(vv));
int32_t v = vv;
char *target = get_overwrite(4, write_count_after);
memcpy(target, &v, 4);
}
void StreamBuffer::overwrite_int64(int64_t write_count_after, int64_t vv) {
assert(safe_to_cast_to_int64(vv));
int64_t v = vv;
char *target = get_overwrite(8, write_count_after);
memcpy(target, &v, 8);
}
void StreamBuffer::overwrite_uint8(int64_t write_count_after, uint64_t vv) {
assert(safe_to_cast_to_uint8(vv));
uint8_t v = vv;
char *target = get_overwrite(1, write_count_after);
memcpy(target, &v, 1);
}
void StreamBuffer::overwrite_uint16(int64_t write_count_after, uint64_t vv) {
assert(safe_to_cast_to_uint16(vv));
uint16_t v = vv;
char *target = get_overwrite(2, write_count_after);
memcpy(target, &v, 2);
}
void StreamBuffer::overwrite_uint32(int64_t write_count_after, uint64_t vv) {
assert(safe_to_cast_to_uint32(vv));
uint32_t v = vv;
char *target = get_overwrite(4, write_count_after);
memcpy(target, &v, 4);
}
void StreamBuffer::overwrite_uint64(int64_t write_count_after, uint64_t vv) {
assert(safe_to_cast_to_uint64(vv));
uint64_t v = vv;
char *target = get_overwrite(8, write_count_after);
memcpy(target, &v, 8);
}
bool StreamBuffer::at_eof() {
return (read_cursor_ == write_cursor_);
}
@@ -350,6 +435,10 @@ static bool streq(const char *str, const char *data) {
return memcmp(str, data, len) == 0;
}
static void write_ztbytes(StreamBuffer *sb, const char *bytes) {
sb->write_bytes(bytes, strlen(bytes));
}
LuaDefine(unittests_streambuffer, "c") {
// An 11-byte fixed-size stream buffer.
StreamBuffer sb11(11, true);
@@ -358,7 +447,7 @@ LuaDefine(unittests_streambuffer, "c") {
assert(sb11.layout_is(0, 0, 11));
// Write a few bytes.
sb11.write_ztbytes("abcdef");
write_ztbytes(&sb11, "abcdef");
assert(sb11.layout_is(0, 6, 5));
// Try reading some bytes.
@@ -381,13 +470,13 @@ LuaDefine(unittests_streambuffer, "c") {
assert(sb11.layout_is(6, 0, 5));
// Write some more bytes into the stream, forcing a shift-left
sb11.write_ztbytes("ghijkl");
write_ztbytes(&sb11, "ghijkl");
assert(sb11.layout_is(0, 6, 5));
// Test buffer wrapping a little more.
assert(streq("ghi", sb11.read_bytes(3)));
assert(sb11.layout_is(3, 3, 5));
sb11.write_ztbytes("mnopqr");
write_ztbytes(&sb11, "mnopqr");
assert(sb11.layout_is(0, 9, 2));
assert(streq("jklmnopqr", sb11.read_bytes(9)));
assert(sb11.layout_is(9, 0, 2));

View File

@@ -237,6 +237,130 @@ public:
};
class StreamBuffer {
public:
// Construct an empty buffer.
StreamBuffer();
// Construct an empty buffer, preallocate the specified amount of space.
StreamBuffer(int64_t size, bool fixed_size);
// Construct a streambuffer that reads from an external block of bytes.
StreamBuffer(const char *s, int64_t len);
// Delete a StreamBuffer.
~StreamBuffer();
// Get the total number of bytes ever read from this buffer.
int64_t read_count() const;
// Get the total number of bytes ever written to this buffer.
int64_t write_count() const;
// Delete all data and (if not fixed-size) free the buffer.
// Also resets the read and write counts.
void clear();
// Write block of bytes into the buffer.
//
// Caution: this function doesn't write the length!
// It just writes the bytes.
//
void write_bytes(const char *bytes, int64_t len);
// Read a block of bytes from the buffer.
//
// May throw StreamEof if the specified number of bytes aren't present.
//
const char *read_bytes(int64_t bytes);
// Write integers and floats into the buffer.
//
// Note that integral parameters are all 64 bits. That's so that I can do
// runtime error checking to verify that the numbers are all in-range.
//
void write_int8(int64_t v);
void write_int16(int64_t v);
void write_int32(int64_t v);
void write_int64(int64_t v);
void write_uint8(uint64_t v);
void write_uint16(uint64_t v);
void write_uint32(uint64_t v);
void write_uint64(uint64_t v);
void write_float(float f);
void write_double(double d);
// Read fixed-size integers from the buffer.
//
// May throw StreamEof if the specified number of bytes aren't present.
//
int8_t read_int8();
int16_t read_int16();
int32_t read_int32();
int64_t read_int64();
uint8_t read_uint8() { return read_int8(); }
uint16_t read_uint16() { return read_int16(); }
uint32_t read_uint32() { return read_int32(); }
uint64_t read_uint64() { return read_int64(); }
float read_float();
double read_double();
// Write other types into the buffer.
//
// Note that strings are preceded by a length field. Reading
// a string works by reading the length field, and then reading
// the correct number of bytes.
//
void write_bool(bool b) { write_int8(b ? 1 : 0); }
void write_hashvalue(const util::HashValue &hv);
void write_string(const std::string &s);
// Read other types from the buffer.
//
// May throw StreamEof if the specified number of bytes aren't present.
// Read string with a length limit will throw 'StreamCorruption' if the
// length is too long.
//
bool read_bool() { return read_int8(); }
util::HashValue read_hashvalue();
std::string read_string();
std::string read_string_limit(int64_t max_allowed);
// Overwrite values previously written to the buffer.
//
// See the comment at the top of this file for an explanation.
//
void overwrite_int8(int64_t write_count_after, int64_t v);
void overwrite_int16(int64_t write_count_after, int64_t v);
void overwrite_int32(int64_t write_count_after, int64_t v);
void overwrite_int64(int64_t write_count_after, int64_t v);
void overwrite_uint8(int64_t write_count_after, uint64_t v);
void overwrite_uint16(int64_t write_count_after, uint64_t v);
void overwrite_uint32(int64_t write_count_after, uint64_t v);
void overwrite_uint64(int64_t write_count_after, uint64_t v);
// Return true if the buffer is empty.
bool at_eof();
// Verify that the buffer is empty, if not, throw StreamCorruption.
void verify_eof();
// Rewind the read cursor to a previous position.
void unread_to(int64_t read_count);
// Rewind the write cursor to a previous position.
void unwrite_to(int64_t write_count);
// Calculate a noncryptographic but good hash of what's in the buffer.
util::HashValue hash() const;
// Use the stream buffer as a lua_Writer.
static int lua_writer(lua_State *L, const void* p, size_t sz, void* ud);
void *lua_writer_ud();
// Use the stream buffer as a lua_Reader.
static const char *lua_reader(lua_State *L, void *data, size_t *size);
void *lua_reader_ud(int64_t bytes);
private:
// Start and end of the allocated block.
char *buf_lo_;
@@ -280,115 +404,10 @@ private:
// Implementation for the overwrite_int functions.
char *get_overwrite(int64_t size, int64_t write_count_after);
// This is mainly for unit testing.
// This is for unit testing.
bool layout_is(int64_t a, int64_t b, int64_t c);
friend int unittests_streambuffer(lua_State *L);
public:
// Construct an empty buffer.
StreamBuffer();
// Construct an empty buffer, preallocate the specified amount of space.
StreamBuffer(int64_t size, bool fixed_size);
// Construct a streambuffer that reads from an external block of bytes.
StreamBuffer(const char *s, int64_t len);
// Delete a StreamBuffer.
~StreamBuffer();
// Get the total number of bytes ever read from this buffer.
int64_t read_count() const;
// Get the total number of bytes ever written to this buffer.
int64_t write_count() const;
// Delete all data and (if not fixed-size) free the buffer.
// Also resets the read and write counts.
void clear();
// Alloc_space and wrote_space need to be invoked together.
char *alloc_space(int64_t bytes);
void wrote_space(int64_t bytes);
// Write numbers into the buffer.
void write_int8(int8_t v);
void write_int16(int16_t v);
void write_int32(int32_t v);
void write_int64(int64_t v);
void write_float(float f);
void write_double(double d);
void write_hashvalue(const util::HashValue &hv);
void write_uint8(uint8_t v) { write_int8(v); }
void write_uint16(uint16_t v) { write_int16(v); }
void write_uint32(uint32_t v) { write_int32(v); }
void write_uint64(uint64_t v) { write_int64(v); }
void write_size(size_t sz) { write_int64(sz); }
void write_bool(bool b) { write_int8(b ? 1 : 0); }
// Write strings or blocks of bytes into the buffer.
void write_string(const std::string &s);
void write_bytes(const char *bytes, int64_t len);
void write_ztbytes(const char *bytes);
// Overwrite values previously written to the buffer.
void overwrite_int8(int64_t write_count_after, int8_t v);
void overwrite_int16(int64_t write_count_after, int16_t v);
void overwrite_int32(int64_t write_count_after, int32_t v);
void overwrite_int64(int64_t write_count_after, int64_t v);
void overwrite_uint8(int64_t write_count_after, uint8_t v) { overwrite_int8(write_count_after, v); }
void overwrite_uint16(int64_t write_count_after, uint16_t v) { overwrite_int16(write_count_after, v); }
void overwrite_uint32(int64_t write_count_after, uint32_t v) { overwrite_int32(write_count_after, v); }
void overwrite_uint64(int64_t write_count_after, uint64_t v) { overwrite_int64(write_count_after, v); }
// Read numbers from the buffer. May throw StreamEof.
int8_t read_int8();
int16_t read_int16();
int32_t read_int32();
int64_t read_int64();
float read_float();
double read_double();
util::HashValue read_hashvalue();
uint8_t read_uint8() { return read_int8(); }
uint16_t read_uint16() { return read_int16(); }
uint32_t read_uint32() { return read_int32(); }
uint64_t read_uint64() { return read_int64(); }
bool read_bool() { return read_int8(); }
// May throw StreamEof or StreamCorruption.
size_t read_size();
size_t read_size_limit(size_t limit);
// Read a string of no more than the specified length.
// May throw StreamEof or StreamCorruption.
std::string read_string();
std::string read_string_limit(int64_t max_allowed);
// Read a block of bytes. May throw StreamEof.
const char *read_bytes(int64_t bytes);
// Return true if the buffer is empty.
bool at_eof();
// Verify that the buffer is empty, if not, throw StreamCorruption.
void verify_eof();
// Rewind the read cursor to a previous position.
void unread_to(int64_t read_count);
// Rewind the write cursor to a previous position.
void unwrite_to(int64_t write_count);
// Calculate a noncryptographic but good hash of what's in the buffer.
util::HashValue hash() const;
// Use the stream buffer as a lua_Writer.
static int lua_writer(lua_State *L, const void* p, size_t sz, void* ud);
void *lua_writer_ud();
// Use the stream buffer as a lua_Reader.
static const char *lua_reader(lua_State *L, void *data, size_t *size);
void *lua_reader_ud(int64_t bytes);
};

View File

@@ -433,7 +433,7 @@ void World::serialize(StreamBuffer *sb) {
lua_snap_.serialize(sb);
id_global_pool_.serialize(sb);
thread_sched_.serialize(sb);
sb->write_size(tangibles_.size());
sb->write_uint32(tangibles_.size());
for (const auto &p : tangibles_) {
sb->write_int64(p.first);
p.second->serialize(sb);
@@ -454,7 +454,7 @@ void World::deserialize(StreamBuffer *sb) {
p.second->plane_item_.set_id(0);
}
// Deserialize tangibles.
size_t ntan = sb->read_size();
size_t ntan = sb->read_uint32();
for (size_t i = 0; i < ntan; i++) {
int64_t id = sb->read_int64();
std::unique_ptr<Tangible> &t = tangibles_[id];