Rename serializer -> encoder.

1 files changed, 321 insertions, 0 deletions

diff --git a/src/upb_encoder.c b/src/upb_encoder.c
new file mode 100644
index 0000000..f67d39d
--- /dev/null
+++ b/src/upb_encoder.c
@@ -0,0 +1,321 @@
+/*
+ * upb - a minimalist implementation of protocol buffers.
+ *
+ * Copyright (c) 2009 Joshua Haberman.  See LICENSE for details.
+ */
+
+#include "upb_encoder.h"
+#include "descriptor.h"
+
+/* Functions for calculating sizes. *******************************************/
+
+static size_t upb_v_uint64_t_size(uint64_t val) {
+#ifdef __GNUC__
+  int high_bit = 63 - __builtin_clzll(val);  // 0-based, undef if val == 0.
+#else
+  int high_bit = 0;
+  uint64_t tmp = val;
+  while(tmp >>= 1) high_bit++;
+#endif
+  return val == 0 ? 1 : high_bit / 7 + 1;
+}
+
+static size_t upb_v_int32_t_size(int32_t val) {
+  // v_uint32's are sign-extended to maintain wire compatibility with int64s.
+  return upb_v_uint64_t_size((int64_t)val);
+}
+static size_t upb_v_uint32_t_size(uint32_t val) {
+  return upb_v_uint64_t_size(val);
+}
+static size_t upb_f_uint64_t_size(uint64_t val) {
+  (void)val;  // Length is independent of value.
+  return sizeof(uint64_t);
+}
+static size_t upb_f_uint32_t_size(uint32_t val) {
+  (void)val;  // Length is independent of value.
+  return sizeof(uint32_t);
+}
+
+// The biggest possible single value is a 10-byte varint.
+#define UPB_MAX_ENCODED_SIZE 10
+
+
+/* Functions to write wire values. ********************************************/
+
+// Since we know in advance the longest that the value could be, we always make
+// sure that our buffer is long enough.  This saves us from having to perform
+// bounds checks.
+
+// Puts a varint (wire type: UPB_WIRE_TYPE_VARINT).
+static uint8_t *upb_put_v_uint64_t(uint8_t *buf, uint64_t val)
+{
+  do {
+    uint8_t byte = val & 0x7f;
+    val >>= 7;
+    if(val) byte |= 0x80;
+    *buf++ = byte;
+  } while(val);
+  return buf;
+}
+
+// Puts an unsigned 32-bit varint, verbatim.  Never uses the high 64 bits.
+static uint8_t *upb_put_v_uint32_t(uint8_t *buf, uint32_t val)
+{
+  return upb_put_v_uint64_t(buf, val);
+}
+
+// Puts a signed 32-bit varint, first sign-extending to 64-bits.  We do this to
+// maintain wire-compatibility with 64-bit signed integers.
+static uint8_t *upb_put_v_int32_t(uint8_t *buf, int32_t val)
+{
+  return upb_put_v_uint64_t(buf, (int64_t)val);
+}
+
+static void upb_put32(uint8_t *buf, uint32_t val) {
+  buf[0] = val & 0xff;
+  buf[1] = (val >> 8) & 0xff;
+  buf[2] = (val >> 16) & 0xff;
+  buf[3] = (val >> 24);
+}
+
+// Puts a fixed-length 32-bit integer (wire type: UPB_WIRE_TYPE_32BIT).
+static uint8_t *upb_put_f_uint32_t(uint8_t *buf, uint32_t val)
+{
+  uint8_t *uint32_end = buf + sizeof(uint32_t);
+#if UPB_UNALIGNED_READS_OK
+  *(uint32_t*)buf = val;
+#else
+  upb_put32(buf, val);
+#endif
+  return uint32_end;
+}
+
+// Puts a fixed-length 64-bit integer (wire type: UPB_WIRE_TYPE_64BIT).
+static uint8_t *upb_put_f_uint64_t(uint8_t *buf, uint64_t val)
+{
+  uint8_t *uint64_end = buf + sizeof(uint64_t);
+#if UPB_UNALIGNED_READS_OK
+  *(uint64_t*)buf = val;
+#else
+  upb_put32(buf, (uint32_t)val);
+  upb_put32(buf, (uint32_t)(val >> 32));
+#endif
+  return uint64_end;
+}
+
+/* Functions to write .proto values. ******************************************/
+
+/* Performs zig-zag encoding, which is used by sint32 and sint64. */
+static uint32_t upb_zzenc_32(int32_t n) { return (n << 1) ^ (n >> 31); }
+static uint64_t upb_zzenc_64(int64_t n) { return (n << 1) ^ (n >> 63); }
+
+/* Use macros to define a set of two functions for each .proto type:
+ *
+ *  // Converts and writes a .proto value into buf.  "end" indicates the end
+ *  // of the current available buffer (if the buffer does not contain enough
+ *  // space UPB_STATUS_NEED_MORE_DATA is returned).  On success, *outbuf will
+ *  // point one past the data that was written.
+ *  uint8_t *upb_put_INT32(uint8_t *buf, int32_t val);
+ *
+ *  // Returns the number of bytes required to encode val.
+ *  size_t upb_get_INT32_size(int32_t val);
+ *
+ *  // Given a .proto value s (source) convert it to a wire value.
+ *  uint32_t upb_vtowv_INT32(int32_t s);
+ */
+
+#define VTOWV(type, wire_t, val_t) \
+  static wire_t upb_vtowv_ ## type(val_t s)
+
+#define PUT(type, v_or_f, wire_t, val_t, member_name) \
+  static uint8_t *upb_put_ ## type(uint8_t *buf, val_t val) { \
+    wire_t tmp = upb_vtowv_ ## type(val); \
+    return upb_put_ ## v_or_f ## _ ## wire_t(buf, tmp); \
+  }
+
+#define T(type, v_or_f, wire_t, val_t, member_name) \
+  static size_t upb_get_ ## type ## _size(val_t val) { \
+    return upb_ ## v_or_f ## _ ## wire_t ## _size(val); \
+  } \
+  VTOWV(type, wire_t, val_t);  /* prototype for PUT below */ \
+  PUT(type, v_or_f, wire_t, val_t, member_name) \
+  VTOWV(type, wire_t, val_t)
+
+T(INT32,    v,  int32_t, int32_t,  int32)   { return (uint32_t)s;     }
+T(INT64,    v, uint64_t, int64_t,  int64)   { return (uint64_t)s;     }
+T(UINT32,   v, uint32_t, uint32_t, uint32)  { return s;               }
+T(UINT64,   v, uint64_t, uint64_t, uint64)  { return s;               }
+T(SINT32,   v, uint32_t, int32_t,  int32)   { return upb_zzenc_32(s); }
+T(SINT64,   v, uint64_t, int64_t,  int64)   { return upb_zzenc_64(s); }
+T(FIXED32,  f, uint32_t, uint32_t, uint32)  { return s;               }
+T(FIXED64,  f, uint64_t, uint64_t, uint64)  { return s;               }
+T(SFIXED32, f, uint32_t, int32_t,  int32)   { return (uint32_t)s;     }
+T(SFIXED64, f, uint64_t, int64_t,  int64)   { return (uint64_t)s;     }
+T(BOOL,     v, uint32_t, bool,     _bool)   { return (uint32_t)s;     }
+T(ENUM,     v, uint32_t, int32_t,  int32)   { return (uint32_t)s;     }
+T(DOUBLE,   f, uint64_t, double,   _double) {
+  union upb_value v;
+  v._double = s;
+  return v.uint64;
+}
+T(FLOAT,    f, uint32_t, float,    _float)  {
+  union upb_value v;
+  v._float = s;
+  return v.uint32;
+}
+#undef VTOWV
+#undef PUT
+#undef T
+
+uint8_t *upb_encode_value(uint8_t *buf, upb_field_type_t ft,
+                          union upb_value v)
+{
+#define CASE(t, member_name) \
+  case UPB_TYPE(t): return upb_put_ ## t(buf, v.member_name);
+  switch(ft) {
+    CASE(DOUBLE,   _double)
+    CASE(FLOAT,    _float)
+    CASE(INT32,    int32)
+    CASE(INT64,    int64)
+    CASE(UINT32,   uint32)
+    CASE(UINT64,   uint64)
+    CASE(SINT32,   int32)
+    CASE(SINT64,   int64)
+    CASE(FIXED32,  uint32)
+    CASE(FIXED64,  uint64)
+    CASE(SFIXED32, int32)
+    CASE(SFIXED64, int64)
+    CASE(BOOL,     _bool)
+    CASE(ENUM,     int32)
+    default: assert(false); return buf;
+  }
+#undef CASE
+}
+
+uint8_t *_upb_put_tag(uint8_t *buf, upb_field_number_t fn, upb_wire_type_t wt)
+{
+  return upb_put_UINT32(buf, wt | (fn << 3));
+}
+
+
+/* upb_sink callbacks *********************************************************/
+
+struct upb_encoder {
+  upb_sink base;
+  //upb_bytesink *bytesink;
+  uint32_t *sizes;
+  int size_offset;
+};
+
+
+// Within one callback we may need to encode up to two separate values.
+#define UPB_ENCODER_BUFSIZE (UPB_MAX_ENCODED_SIZE * 2)
+
+static upb_sink_status _upb_encoder_push_buf(upb_encoder *s, const uint8_t *buf,
+                                             size_t len)
+{
+  // TODO: conjure a upb_strptr that points to buf.
+  //upb_strptr ptr;
+  (void)s;
+  (void)buf;
+  size_t written = 5;// = upb_bytesink_onbytes(s->bytesink, ptr);
+  if(written < len) {
+    // TODO: mark to skip "written" bytes next time.
+    return UPB_SINK_STOP;
+  } else {
+    return UPB_SINK_CONTINUE;
+  }
+}
+
+static upb_sink_status _upb_encoder_valuecb(upb_sink *sink,
+                                            struct upb_fielddef *f,
+                                            union upb_value val)
+{
+  upb_encoder *s = (upb_encoder*)sink;
+  uint8_t buf[UPB_ENCODER_BUFSIZE], *ptr = buf;
+  upb_wire_type_t wt = upb_type_info[f->type].expected_wire_type;
+  // TODO: handle packed encoding.
+  ptr = _upb_put_tag(ptr, f->number, wt);
+  ptr = upb_encode_value(ptr, f->type, val);
+  return _upb_encoder_push_buf(s, buf, ptr - buf);
+}
+
+static upb_sink_status _upb_encoder_strcb(upb_sink *sink,
+                                          struct upb_fielddef *f,
+                                          upb_strptr str,
+                                          int32_t start, uint32_t end)
+{
+  upb_encoder *s = (upb_encoder*)sink;
+  uint8_t buf[UPB_ENCODER_BUFSIZE], *ptr = buf;
+  if(start >= 0) {
+    ptr = _upb_put_tag(ptr, f->number, UPB_WIRE_TYPE_DELIMITED);
+    ptr = upb_put_UINT32(ptr, end - start);
+  }
+  // TODO: properly handle partially consumed strings and partially supplied
+  // strings.
+  _upb_encoder_push_buf(s, buf, ptr - buf);
+  return _upb_encoder_push_buf(s, (uint8_t*)upb_string_getrobuf(str), end - start);
+}
+
+static upb_sink_status _upb_encoder_startcb(upb_sink *sink,
+                                            struct upb_fielddef *f)
+{
+  upb_encoder *s = (upb_encoder*)sink;
+  uint8_t buf[UPB_ENCODER_BUFSIZE], *ptr = buf;
+  if(f->type == UPB_TYPE(GROUP)) {
+    ptr = _upb_put_tag(ptr, f->number, UPB_WIRE_TYPE_START_GROUP);
+  } else {
+    ptr = _upb_put_tag(ptr, f->number, UPB_WIRE_TYPE_DELIMITED);
+    ptr = upb_put_UINT32(ptr, s->sizes[--s->size_offset]);
+  }
+  return _upb_encoder_push_buf(s, buf, ptr - buf);
+}
+
+static upb_sink_status _upb_encoder_endcb(upb_sink *sink,
+                                          struct upb_fielddef *f)
+{
+  upb_encoder *s = (upb_encoder*)sink;
+  uint8_t buf[UPB_ENCODER_BUFSIZE], *ptr = buf;
+  if(f->type != UPB_TYPE(GROUP)) return UPB_SINK_CONTINUE;
+  ptr = _upb_put_tag(ptr, f->number, UPB_WIRE_TYPE_END_GROUP);
+  return _upb_encoder_push_buf(s, buf, ptr - buf);
+}
+
+upb_sink_callbacks _upb_encoder_sink_vtbl = {
+  _upb_encoder_valuecb,
+  _upb_encoder_strcb,
+  _upb_encoder_startcb,
+  _upb_encoder_endcb
+};
+
+
+/* Public Interface ***********************************************************/
+
+size_t upb_get_encoded_size(union upb_value v, struct upb_fielddef *f)
+{
+#define CASE(t, member_name) \
+  case UPB_TYPE(t): return upb_get_ ## t ## _size(v.member_name);
+  switch(f->type) {
+    CASE(DOUBLE,   _double)
+    CASE(FLOAT,    _float)
+    CASE(INT32,    int32)
+    CASE(INT64,    int64)
+    CASE(UINT32,   uint32)
+    CASE(UINT64,   uint64)
+    CASE(SINT32,   int32)
+    CASE(SINT64,   int64)
+    CASE(FIXED32,  uint32)
+    CASE(FIXED64,  uint64)
+    CASE(SFIXED32, int32)
+    CASE(SFIXED64, int64)
+    CASE(BOOL,     _bool)
+    CASE(ENUM,     int32)
+    default: assert(false); return 0;
+  }
+#undef CASE
+}
+
+size_t upb_get_encoded_tag_size(uint32_t fieldnum) {
+  return upb_v_uint64_t_size((uint64_t)fieldnum << 3);
+}
+