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/*
* upb - a minimalist implementation of protocol buffers.
*
* Copyright (c) 2014 Google Inc. See LICENSE for details.
* Author: Josh Haberman <jhaberman@gmail.com>
*
* Uses YAJL at the moment; this is not exposed publicly and will likely change
* in the future.
*
*/
#include "upb/json/printer.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <yajl/yajl_gen.h>
static void doprint(void *_p, const char *buf, unsigned int len) {
upb_json_printer *p = _p;
// YAJL doesn't support returning an error status here, so we can't properly
// support clients who return a value other than "len" here.
size_t n = upb_bytessink_putbuf(p->output_, p->subc_, buf, len, NULL);
UPB_ASSERT_VAR(n, n == len);
}
// StringPiece; a pointer plus a length.
typedef struct {
const char *ptr;
size_t len;
} strpc;
strpc *newstrpc(upb_handlers *h, const upb_fielddef *f) {
strpc *ret = malloc(sizeof(*ret));
ret->ptr = upb_fielddef_name(f);
ret->len = strlen(ret->ptr);
upb_handlers_addcleanup(h, ret, free);
return ret;
}
#define CHKYAJL(x) if ((x) != yajl_gen_status_ok) return false;
#define CHK(x) if (!(x)) return false;
// Wrapper for yajl_gen_string that takes "const char*" instead of "const
// unsigned char*".
static yajl_gen_status yajl_gen_string2(yajl_gen yajl, const char *ptr,
size_t len) {
return yajl_gen_string(yajl, (const unsigned char *)ptr, len);
}
// Wrappers for yajl_gen_number() that formats floating point values
// according to our custom formats. Right now we use %.8g and %.17g
// for float/double, respectively, to match proto2::util::JsonFormat's
// defaults. May want to change this later.
static yajl_gen_status upbyajl_gen_double(yajl_gen yajl, double val) {
char data[64];
int n = snprintf(data, sizeof(data), "%.17g", val);
CHK(n > 0 && n < sizeof(data));
return yajl_gen_number(yajl, data, n);
}
static yajl_gen_status upbyajl_gen_float(yajl_gen yajl, float val) {
char data[64];
int n = snprintf(data, sizeof(data), "%.8g", val);
CHK(n > 0 && n < sizeof(data));
return yajl_gen_number(yajl, data, n);
}
static yajl_gen_status upbyajl_gen_uint64(yajl_gen yajl,
unsigned long long val) {
char data[64];
int n = snprintf(data, sizeof(data), "%llu", val);
CHK(n > 0 && n < sizeof(data));
return yajl_gen_number(yajl, data, n);
}
static bool putkey(void *closure, const void *handler_data) {
upb_json_printer *p = closure;
const strpc *key = handler_data;
CHKYAJL(yajl_gen_string2(p->yajl_gen_, key->ptr, key->len));
return true;
}
#define TYPE_HANDLERS(type, yajlfunc) \
static bool put##type(void *closure, const void *handler_data, type val) { \
upb_json_printer *p = closure; \
UPB_UNUSED(handler_data); \
CHKYAJL(yajlfunc(p->yajl_gen_, val)); \
return true; \
} \
static bool scalar_##type(void *closure, const void *handler_data, \
type val) { \
CHK(putkey(closure, handler_data)); \
CHK(put##type(closure, handler_data, val)); \
return true; \
}
TYPE_HANDLERS(double, upbyajl_gen_double);
TYPE_HANDLERS(float, upbyajl_gen_float);
TYPE_HANDLERS(bool, yajl_gen_bool);
TYPE_HANDLERS(int32_t, yajl_gen_integer);
TYPE_HANDLERS(uint32_t, yajl_gen_integer);
TYPE_HANDLERS(int64_t, yajl_gen_integer);
TYPE_HANDLERS(uint64_t, upbyajl_gen_uint64);
#undef TYPE_HANDLERS
static void *startsubmsg(void *closure, const void *handler_data) {
return putkey(closure, handler_data) ? closure : UPB_BREAK;
}
static bool startmap(void *closure, const void *handler_data) {
UPB_UNUSED(handler_data);
upb_json_printer *p = closure;
if (p->depth_++ == 0) {
upb_bytessink_start(p->output_, 0, &p->subc_);
}
CHKYAJL(yajl_gen_map_open(p->yajl_gen_));
return true;
}
static bool endmap(void *closure, const void *handler_data, upb_status *s) {
UPB_UNUSED(handler_data);
UPB_UNUSED(s);
upb_json_printer *p = closure;
if (--p->depth_ == 0) {
upb_bytessink_end(p->output_);
}
CHKYAJL(yajl_gen_map_close(p->yajl_gen_));
return true;
}
static void *startseq(void *closure, const void *handler_data) {
upb_json_printer *p = closure;
CHK(putkey(closure, handler_data));
CHKYAJL(yajl_gen_array_open(p->yajl_gen_));
return closure;
}
static bool endseq(void *closure, const void *handler_data) {
UPB_UNUSED(handler_data);
upb_json_printer *p = closure;
CHKYAJL(yajl_gen_array_close(p->yajl_gen_));
return true;
}
static size_t putstr(void *closure, const void *handler_data, const char *str,
size_t len, const upb_bufhandle *handle) {
UPB_UNUSED(handle);
upb_json_printer *p = closure;
CHKYAJL(yajl_gen_string2(p->yajl_gen_, str, len));
return len;
}
// This has to Base64 encode the bytes, because JSON has no "bytes" type.
static size_t putbytes(void *closure, const void *handler_data, const char *str,
size_t len, const upb_bufhandle *handle) {
UPB_UNUSED(handle);
upb_json_printer *p = closure;
// This is the regular base64, not the "web-safe" version.
static const char base64[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
// Base64-encode.
char data[16000];
const char *limit = data + sizeof(data);
const unsigned char *from = (const unsigned char*)str;
char *to = data;
size_t remaining = len;
while (remaining > 2) {
// TODO(haberman): handle encoded lengths > sizeof(data)
UPB_ASSERT_VAR(limit, (limit - to) >= 4);
to[0] = base64[from[0] >> 2];
to[1] = base64[((from[0] & 0x3) << 4) | (from[1] >> 4)];
to[2] = base64[((from[1] & 0xf) << 2) | (from[2] >> 6)];
to[3] = base64[from[2] & 0x3f];
remaining -= 3;
to += 4;
from += 3;
}
switch (remaining) {
case 2:
to[0] = base64[from[0] >> 2];
to[1] = base64[((from[0] & 0x3) << 4) | (from[1] >> 4)];
to[2] = base64[(from[1] & 0xf) << 2];
to[3] = '=';
to += 4;
from += 2;
break;
case 1:
to[0] = base64[from[0] >> 2];
to[1] = base64[((from[0] & 0x3) << 4)];
to[2] = '=';
to[3] = '=';
to += 4;
from += 1;
break;
}
size_t bytes = to - data;
if (yajl_gen_string2(p->yajl_gen_, data, bytes) != yajl_gen_status_ok) {
return 0;
}
return len;
}
static size_t scalar_str(void *closure, const void *handler_data,
const char *str, size_t len,
const upb_bufhandle *handle) {
CHK(putkey(closure, handler_data));
CHK(putstr(closure, handler_data, str, len, handle));
return len;
}
static size_t scalar_bytes(void *closure, const void *handler_data,
const char *str, size_t len,
const upb_bufhandle *handle) {
CHK(putkey(closure, handler_data));
CHK(putbytes(closure, handler_data, str, len, handle));
return len;
}
void sethandlers(const void *closure, upb_handlers *h) {
UPB_UNUSED(closure);
upb_handlerattr empty_attr = UPB_HANDLERATTR_INITIALIZER;
upb_handlers_setstartmsg(h, startmap, &empty_attr);
upb_handlers_setendmsg(h, endmap, &empty_attr);
#define TYPE(type, name, ctype) \
case type: \
if (upb_fielddef_isseq(f)) { \
upb_handlers_set##name(h, f, put##ctype, &empty_attr); \
} else { \
upb_handlers_set##name(h, f, scalar_##ctype, &name_attr); \
} \
break;
upb_msg_iter i;
upb_msg_begin(&i, upb_handlers_msgdef(h));
for(; !upb_msg_done(&i); upb_msg_next(&i)) {
const upb_fielddef *f = upb_msg_iter_field(&i);
upb_handlerattr name_attr = UPB_HANDLERATTR_INITIALIZER;
upb_handlerattr_sethandlerdata(&name_attr, newstrpc(h, f));
if (upb_fielddef_isseq(f)) {
upb_handlers_setstartseq(h, f, startseq, &name_attr);
upb_handlers_setendseq(h, f, endseq, &empty_attr);
}
switch (upb_fielddef_type(f)) {
TYPE(UPB_TYPE_FLOAT, float, float);
TYPE(UPB_TYPE_DOUBLE, double, double);
TYPE(UPB_TYPE_BOOL, bool, bool);
TYPE(UPB_TYPE_ENUM, int32, int32_t);
TYPE(UPB_TYPE_INT32, int32, int32_t);
TYPE(UPB_TYPE_UINT32, uint32, uint32_t);
TYPE(UPB_TYPE_INT64, int64, int64_t);
TYPE(UPB_TYPE_UINT64, uint64, uint64_t);
case UPB_TYPE_STRING:
// XXX: this doesn't support strings that span buffers yet.
if (upb_fielddef_isseq(f)) {
upb_handlers_setstring(h, f, putstr, &empty_attr);
} else {
upb_handlers_setstring(h, f, scalar_str, &name_attr);
}
break;
case UPB_TYPE_BYTES:
// XXX: this doesn't support strings that span buffers yet.
if (upb_fielddef_isseq(f)) {
upb_handlers_setstring(h, f, putbytes, &empty_attr);
} else {
upb_handlers_setstring(h, f, scalar_bytes, &name_attr);
}
break;
case UPB_TYPE_MESSAGE:
if (!upb_fielddef_isseq(f)) {
upb_handlers_setstartsubmsg(h, f, startsubmsg, &name_attr);
}
break;
}
upb_handlerattr_uninit(&name_attr);
}
upb_handlerattr_uninit(&empty_attr);
#undef TYPE
}
// YAJL unfortunately does not support stack allocation, nor resetting an
// allocated object, so we have to allocate on the heap and reallocate whenever
// there is a reset.
static void reset(upb_json_printer *p, bool free) {
if (free) {
yajl_gen_free(p->yajl_gen_);
}
p->yajl_gen_ = yajl_gen_alloc(NULL);
yajl_gen_config(p->yajl_gen_, yajl_gen_validate_utf8, 0);
yajl_gen_config(p->yajl_gen_, yajl_gen_print_callback, &doprint, p);
}
/* Public API *****************************************************************/
void upb_json_printer_init(upb_json_printer *p, const upb_handlers *h) {
p->output_ = NULL;
p->depth_ = 0;
reset(p, false);
upb_sink_reset(&p->input_, h, p);
}
void upb_json_printer_uninit(upb_json_printer *p) {
yajl_gen_free(p->yajl_gen_);
}
void upb_json_printer_reset(upb_json_printer *p) {
p->depth_ = 0;
reset(p, true);
}
void upb_json_printer_resetoutput(upb_json_printer *p, upb_bytessink *output) {
upb_json_printer_reset(p);
p->output_ = output;
}
upb_sink *upb_json_printer_input(upb_json_printer *p) {
return &p->input_;
}
const upb_handlers *upb_json_printer_newhandlers(const upb_msgdef *md,
const void *owner) {
return upb_handlers_newfrozen(md, owner, sethandlers, NULL);
}
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