src/out-default.c - third_party/libplist - Git at Google

 /*
  * out-default.c
  * libplist default *output-only* format - NOT for machine parsing
  *
  * Copyright (c) 2022-2023 Nikias Bassen All Rights Reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */

 #ifdef HAVE_CONFIG_H
 #include <config.h>
 #endif

 #include <string.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>

 #include <inttypes.h>
 #include <ctype.h>
 #include <math.h>
 #include <limits.h>

 #include <node.h>

 #include "plist.h"
 #include "strbuf.h"
 #include "time64.h"

 #define MAC_EPOCH 978307200

 static size_t dtostr(char *buf, size_t bufsize, double realval)
 {
     size_t len = 0;
     if (isnan(realval)) {
         len = snprintf(buf, bufsize, "nan");
     } else if (isinf(realval)) {
         len = snprintf(buf, bufsize, "%cinfinity", (realval > 0.0) ? '+' : '-');
     } else if (realval == 0.0f) {
         len = snprintf(buf, bufsize, "0.0");
     } else {
         size_t i = 0;
         len = snprintf(buf, bufsize, "%.*g", 17, realval);
         for (i = 0; buf && i < len; i++) {
             if (buf[i] == ',') {
                 buf[i] = '.';
                 break;
             } else if (buf[i] == '.') {
                 break;
             }
         }
     }
     return len;
 }

 static int node_to_string(node_t node, bytearray_t **outbuf, uint32_t depth, uint32_t indent, int partial_data)
 {
     plist_data_t node_data = NULL;

     char *val = NULL;
     size_t val_len = 0;

     uint32_t i = 0;

     if (!node)
         return PLIST_ERR_INVALID_ARG;

     node_data = plist_get_data(node);

     switch (node_data->type)
     {
     case PLIST_BOOLEAN:
     {
         if (node_data->boolval) {
             str_buf_append(*outbuf, "true", 4);
         } else {
             str_buf_append(*outbuf, "false", 5);
         }
     }
     break;

     case PLIST_NULL:
         str_buf_append(*outbuf, "null", 4);
 	break;

     case PLIST_INT:
         val = (char*)malloc(64);
         if (node_data->length == 16) {
             val_len = snprintf(val, 64, "%"PRIu64, node_data->intval);
         } else {
             val_len = snprintf(val, 64, "%"PRIi64, node_data->intval);
         }
         str_buf_append(*outbuf, val, val_len);
         free(val);
         break;

     case PLIST_REAL:
         val = (char*)malloc(64);
         val_len = dtostr(val, 64, node_data->realval);
         str_buf_append(*outbuf, val, val_len);
         free(val);
         break;

     case PLIST_STRING:
     case PLIST_KEY: {
         const char *charmap[32] = {
             "\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006", "\\u0007",
             "\\b",     "\\t",     "\\n",     "\\u000b", "\\f",     "\\r",     "\\u000e", "\\u000f",
             "\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017",
             "\\u0018", "\\u0019", "\\u001a", "\\u001b", "\\u001c", "\\u001d", "\\u001e", "\\u001f",
         };
         size_t j = 0;
         size_t len = 0;
         off_t start = 0;
         off_t cur = 0;

         str_buf_append(*outbuf, "\"", 1);

         len = node_data->length;
         for (j = 0; j < len; j++) {
             unsigned char ch = (unsigned char)node_data->strval[j];
             if (ch < 0x20) {
                 str_buf_append(*outbuf, node_data->strval + start, cur - start);
                 str_buf_append(*outbuf, charmap[ch], (charmap[ch][1] == 'u') ? 6 : 2);
                 start = cur+1;
             } else if (ch == '"') {
                 str_buf_append(*outbuf, node_data->strval + start, cur - start);
                 str_buf_append(*outbuf, "\\\"", 2);
                 start = cur+1;
             }
             cur++;
         }
         str_buf_append(*outbuf, node_data->strval + start, cur - start);

         str_buf_append(*outbuf, "\"", 1);
         } break;

     case PLIST_ARRAY: {
         str_buf_append(*outbuf, "[", 1);
         node_t ch;
         uint32_t cnt = 0;
         for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
             if (cnt > 0) {
                 str_buf_append(*outbuf, ",", 1);
             }
             str_buf_append(*outbuf, "\n", 1);
             for (i = 0; i <= depth+indent; i++) {
                 str_buf_append(*outbuf, "  ", 2);
             }
             int res = node_to_string(ch, outbuf, depth+1, indent, partial_data);
             if (res < 0) {
                 return res;
             }
             cnt++;
         }
         if (cnt > 0) {
             str_buf_append(*outbuf, "\n", 1);
             for (i = 0; i < depth+indent; i++) {
                 str_buf_append(*outbuf, "  ", 2);
             }
         }
         str_buf_append(*outbuf, "]", 1);
         } break;
     case PLIST_DICT: {
         str_buf_append(*outbuf, "{", 1);
         node_t ch;
         uint32_t cnt = 0;
         for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
             if (cnt > 0 && cnt % 2 == 0) {
                 str_buf_append(*outbuf, ",", 1);
             }
             if (cnt % 2 == 0) {
                 str_buf_append(*outbuf, "\n", 1);
                 for (i = 0; i <= depth+indent; i++) {
                     str_buf_append(*outbuf, "  ", 2);
                 }
             }
             int res = node_to_string(ch, outbuf, depth+1, indent, partial_data);
             if (res < 0) {
                 return res;
             }
             if (cnt % 2 == 0) {
                 str_buf_append(*outbuf, ": ", 2);
             }
             cnt++;
         }
         if (cnt > 0) {
             str_buf_append(*outbuf, "\n", 1);
             for (i = 0; i < depth+indent; i++) {
                 str_buf_append(*outbuf, "  ", 2);
             }
         }
         str_buf_append(*outbuf, "}", 1);
         } break;
     case PLIST_DATA:
         {
             str_buf_append(*outbuf, "<", 1);
             size_t len = node_data->length;
             char charb[4];
             if (!partial_data || len <= 24) {
                 for (i = 0; i < len; i++) {
                     if (i > 0 && (i % 4 == 0))
                         str_buf_append(*outbuf, " ", 1);
                     sprintf(charb, "%02x", (unsigned char)node_data->buff[i]);
                     str_buf_append(*outbuf, charb, 2);
                 }
             } else {
                 for (i = 0; i < 16; i++) {
                     if (i > 0 && (i % 4 == 0))
                         str_buf_append(*outbuf, " ", 1);
                     sprintf(charb, "%02x", (unsigned char)node_data->buff[i]);
                     str_buf_append(*outbuf, charb, 2);
                 }
                 str_buf_append(*outbuf, " ... ", 5);
                 for (i = len - 8; i < len; i++) {
                     sprintf(charb, "%02x", (unsigned char)node_data->buff[i]);
                     str_buf_append(*outbuf, charb, 2);
                     if (i > 0 && i < len-1 && (i % 4 == 0))
                         str_buf_append(*outbuf, " ", 1);
                 }
             }
             str_buf_append(*outbuf, ">", 1);
         }
         break;
     case PLIST_DATE:
         {
             Time64_T timev = (Time64_T)node_data->realval + MAC_EPOCH;
             struct TM _btime;
             struct TM *btime = gmtime64_r(&timev, &_btime);
             if (btime) {
                 val = (char*)calloc(1, 26);
                 struct tm _tmcopy;
                 copy_TM64_to_tm(btime, &_tmcopy);
                 val_len = strftime(val, 26, "%Y-%m-%d %H:%M:%S +0000", &_tmcopy);
                 if (val_len > 0) {
                     str_buf_append(*outbuf, val, val_len);
                 }
                 free(val);
                 val = NULL;
             }
         }
         break;
     case PLIST_UID:
         {
             str_buf_append(*outbuf, "CF$UID:", 7);
             val = (char*)malloc(64);
             if (node_data->length == 16) {
                 val_len = snprintf(val, 64, "%"PRIu64, node_data->intval);
             } else {
                 val_len = snprintf(val, 64, "%"PRIi64, node_data->intval);
             }
             str_buf_append(*outbuf, val, val_len);
             free(val);
         }
         break;
     default:
         return PLIST_ERR_UNKNOWN;
     }

     return PLIST_ERR_SUCCESS;
 }

 #define PO10i_LIMIT (INT64_MAX/10)

 /* based on https://stackoverflow.com/a/4143288 */
 static int num_digits_i(int64_t i)
 {
     int n;
     int64_t po10;
     n=1;
     if (i < 0) {
         i = (i == INT64_MIN) ? INT64_MAX : -i;
         n++;
     }
     po10=10;
     while (i>=po10) {
         n++;
         if (po10 > PO10i_LIMIT) break;
         po10*=10;
     }
     return n;
 }

 #define PO10u_LIMIT (UINT64_MAX/10)

 /* based on https://stackoverflow.com/a/4143288 */
 static int num_digits_u(uint64_t i)
 {
     int n;
     uint64_t po10;
     n=1;
     po10=10;
     while (i>=po10) {
         n++;
         if (po10 > PO10u_LIMIT) break;
         po10*=10;
     }
     return n;
 }

 static int node_estimate_size(node_t node, uint64_t *size, uint32_t depth, uint32_t indent, int partial_data)
 {
     plist_data_t data;
     if (!node) {
         return PLIST_ERR_INVALID_ARG;
     }
     data = plist_get_data(node);
     if (node->children) {
         node_t ch;
         unsigned int n_children = node_n_children(node);
         for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
             int res = node_estimate_size(ch, size, depth + 1, indent, partial_data);
             if (res < 0) {
                 return res;
             }
         }
         switch (data->type) {
         case PLIST_DICT:
             *size += 2; // '{' and '}'
             *size += n_children-1; // number of ':' and ','
             *size += n_children; // number of '\n' and extra space
             *size += (uint64_t)n_children * (depth+indent+1); // indent for every 2nd child
             *size += indent+1; // additional '\n'
             break;
         case PLIST_ARRAY:
             *size += 2; // '[' and ']'
             *size += n_children-1; // number of ','
             *size += n_children; // number of '\n'
             *size += (uint64_t)n_children * ((depth+indent+1)<<1); // indent for every child
             *size += indent+1; // additional '\n'
             break;
         default:
             break;
 	}
         *size += ((depth+indent) << 1); // indent for {} and []
     } else {
         switch (data->type) {
         case PLIST_STRING:
         case PLIST_KEY:
             *size += data->length;
             *size += 2;
             break;
         case PLIST_INT:
             if (data->length == 16) {
                 *size += num_digits_u(data->intval);
             } else {
                 *size += num_digits_i((int64_t)data->intval);
             }
             break;
         case PLIST_REAL:
             *size += dtostr(NULL, 0, data->realval);
             break;
         case PLIST_BOOLEAN:
             *size += ((data->boolval) ? 4 : 5);
             break;
         case PLIST_NULL:
             *size += 4;
             break;
         case PLIST_DICT:
         case PLIST_ARRAY:
             *size += 2;
             break;
         case PLIST_DATA:
             *size += 2; // < and >
             if (partial_data) {
                 *size += 58;
             } else {
                 *size += data->length * 2;
                 *size += data->length / 4; // space between 4 byte groups
             }
             break;
         case PLIST_DATE:
             *size += 25;
             break;
         case PLIST_UID:
             *size += 7; // "CF$UID:"
             *size += num_digits_u(data->intval);
             break;
         default:
 #ifdef DEBUG
             fprintf(stderr, "%s: invalid node type encountered\n", __func__);
 #endif
             return PLIST_ERR_UNKNOWN;
         }
     }
     if (depth == 0) {
         *size += 1; // final newline
     }
     return PLIST_ERR_SUCCESS;
 }

 static plist_err_t _plist_write_to_strbuf(plist_t plist, strbuf_t *outbuf, plist_write_options_t options)
 {
     uint8_t indent = 0;
     if (options & PLIST_OPT_INDENT) {
         indent = (options >> 24) & 0xFF;
     }
     uint8_t i;
     for (i = 0; i < indent; i++) {
         str_buf_append(outbuf, "  ", 2);
     }
     int res = node_to_string(plist, &outbuf, 0, indent, options & PLIST_OPT_PARTIAL_DATA);
     if (res < 0) {
         return res;
     }
     if (!(options & PLIST_OPT_NO_NEWLINE)) {
         str_buf_append(outbuf, "\n", 1);
     }
     return res;
 }

 plist_err_t plist_write_to_string_default(plist_t plist, char **output, uint32_t* length, plist_write_options_t options)
 {
     uint64_t size = 0;
     int res;

     if (!plist || !output || !length) {
         return PLIST_ERR_INVALID_ARG;
     }

     uint8_t indent = 0;
     if (options & PLIST_OPT_INDENT) {
         indent = (options >> 24) & 0xFF;
     }

     res = node_estimate_size(plist, &size, 0, indent, options & PLIST_OPT_PARTIAL_DATA);
     if (res < 0) {
         return res;
     }

     strbuf_t *outbuf = str_buf_new(size);
     if (!outbuf) {
 #if DEBUG
         fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);
 #endif
         return PLIST_ERR_NO_MEM;
     }

     res = _plist_write_to_strbuf(plist, outbuf, options);
     if (res < 0) {
         str_buf_free(outbuf);
         *output = NULL;
         *length = 0;
         return res;
     }
     str_buf_append(outbuf, "\0", 1);

     *output = outbuf->data;
     *length = outbuf->len - 1;

     outbuf->data = NULL;
     str_buf_free(outbuf);

     return PLIST_ERR_SUCCESS;
 }

 plist_err_t plist_write_to_stream_default(plist_t plist, FILE *stream, plist_write_options_t options)
 {
     if (!plist || !stream) {
         return PLIST_ERR_INVALID_ARG;
     }
     strbuf_t *outbuf = str_buf_new_for_stream(stream);
     if (!outbuf) {
 #if DEBUG
         fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);
 #endif
         return PLIST_ERR_NO_MEM;
     }

     int res = _plist_write_to_strbuf(plist, outbuf, options);
     if (res < 0) {
         str_buf_free(outbuf);
         return res;
     }

     str_buf_free(outbuf);

     return PLIST_ERR_SUCCESS;
 }
	/*
	* out-default.c
	* libplist default output-only format - NOT for machine parsing
	*
	* Copyright (c) 2022-2023 Nikias Bassen All Rights Reserved.
	*
	* This library is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* This library is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with this library; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#ifdef HAVE_CONFIG_H
	#include <config.h>
	#endif

	#include <string.h>
	#include <stdlib.h>
	#include <stdio.h>
	#include <time.h>

	#include <inttypes.h>
	#include <ctype.h>
	#include <math.h>
	#include <limits.h>

	#include <node.h>

	#include "plist.h"
	#include "strbuf.h"
	#include "time64.h"

	#define MAC_EPOCH 978307200

	static size_t dtostr(char *buf, size_t bufsize, double realval)
	{
	size_t len = 0;
	if (isnan(realval)) {
	len = snprintf(buf, bufsize, "nan");
	} else if (isinf(realval)) {
	len = snprintf(buf, bufsize, "%cinfinity", (realval > 0.0) ? '+' : '-');
	} else if (realval == 0.0f) {
	len = snprintf(buf, bufsize, "0.0");
	} else {
	size_t i = 0;
	len = snprintf(buf, bufsize, "%.*g", 17, realval);
	for (i = 0; buf && i < len; i++) {
	if (buf[i] == ',') {
	buf[i] = '.';
	break;
	} else if (buf[i] == '.') {
	break;
	}
	}
	}
	return len;
	}

	static int node_to_string(node_t node, bytearray_t **outbuf, uint32_t depth, uint32_t indent, int partial_data)
	{
	plist_data_t node_data = NULL;

	char *val = NULL;
	size_t val_len = 0;

	uint32_t i = 0;

	if (!node)
	return PLIST_ERR_INVALID_ARG;

	node_data = plist_get_data(node);

	switch (node_data->type)
	{
	case PLIST_BOOLEAN:
	{
	if (node_data->boolval) {
	str_buf_append(*outbuf, "true", 4);
	} else {
	str_buf_append(*outbuf, "false", 5);
	}
	}
	break;

	case PLIST_NULL:
	str_buf_append(*outbuf, "null", 4);
	break;

	case PLIST_INT:
	val = (char*)malloc(64);
	if (node_data->length == 16) {
	val_len = snprintf(val, 64, "%"PRIu64, node_data->intval);
	} else {
	val_len = snprintf(val, 64, "%"PRIi64, node_data->intval);
	}
	str_buf_append(*outbuf, val, val_len);
	free(val);
	break;

	case PLIST_REAL:
	val = (char*)malloc(64);
	val_len = dtostr(val, 64, node_data->realval);
	str_buf_append(*outbuf, val, val_len);
	free(val);
	break;

	case PLIST_STRING:
	case PLIST_KEY: {
	const char *charmap[32] = {
	"\\u0000", "\\u0001", "\\u0002", "\\u0003", "\\u0004", "\\u0005", "\\u0006", "\\u0007",
	"\\b", "\\t", "\\n", "\\u000b", "\\f", "\\r", "\\u000e", "\\u000f",
	"\\u0010", "\\u0011", "\\u0012", "\\u0013", "\\u0014", "\\u0015", "\\u0016", "\\u0017",
	"\\u0018", "\\u0019", "\\u001a", "\\u001b", "\\u001c", "\\u001d", "\\u001e", "\\u001f",
	};
	size_t j = 0;
	size_t len = 0;
	off_t start = 0;
	off_t cur = 0;

	str_buf_append(*outbuf, "\"", 1);

	len = node_data->length;
	for (j = 0; j < len; j++) {
	unsigned char ch = (unsigned char)node_data->strval[j];
	if (ch < 0x20) {
	str_buf_append(*outbuf, node_data->strval + start, cur - start);
	str_buf_append(*outbuf, charmap[ch], (charmap[ch][1] == 'u') ? 6 : 2);
	start = cur+1;
	} else if (ch == '"') {
	str_buf_append(*outbuf, node_data->strval + start, cur - start);
	str_buf_append(*outbuf, "\\\"", 2);
	start = cur+1;
	}
	cur++;
	}
	str_buf_append(*outbuf, node_data->strval + start, cur - start);

	str_buf_append(*outbuf, "\"", 1);
	} break;

	case PLIST_ARRAY: {
	str_buf_append(*outbuf, "[", 1);
	node_t ch;
	uint32_t cnt = 0;
	for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
	if (cnt > 0) {
	str_buf_append(*outbuf, ",", 1);
	}
	str_buf_append(*outbuf, "\n", 1);
	for (i = 0; i <= depth+indent; i++) {
	str_buf_append(*outbuf, " ", 2);
	}
	int res = node_to_string(ch, outbuf, depth+1, indent, partial_data);
	if (res < 0) {
	return res;
	}
	cnt++;
	}
	if (cnt > 0) {
	str_buf_append(*outbuf, "\n", 1);
	for (i = 0; i < depth+indent; i++) {
	str_buf_append(*outbuf, " ", 2);
	}
	}
	str_buf_append(*outbuf, "]", 1);
	} break;
	case PLIST_DICT: {
	str_buf_append(*outbuf, "{", 1);
	node_t ch;
	uint32_t cnt = 0;
	for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
	if (cnt > 0 && cnt % 2 == 0) {
	str_buf_append(*outbuf, ",", 1);
	}
	if (cnt % 2 == 0) {
	str_buf_append(*outbuf, "\n", 1);
	for (i = 0; i <= depth+indent; i++) {
	str_buf_append(*outbuf, " ", 2);
	}
	}
	int res = node_to_string(ch, outbuf, depth+1, indent, partial_data);
	if (res < 0) {
	return res;
	}
	if (cnt % 2 == 0) {
	str_buf_append(*outbuf, ": ", 2);
	}
	cnt++;
	}
	if (cnt > 0) {
	str_buf_append(*outbuf, "\n", 1);
	for (i = 0; i < depth+indent; i++) {
	str_buf_append(*outbuf, " ", 2);
	}
	}
	str_buf_append(*outbuf, "}", 1);
	} break;
	case PLIST_DATA:
	{
	str_buf_append(*outbuf, "<", 1);
	size_t len = node_data->length;
	char charb[4];
	if (!partial_data \|\| len <= 24) {
	for (i = 0; i < len; i++) {
	if (i > 0 && (i % 4 == 0))
	str_buf_append(*outbuf, " ", 1);
	sprintf(charb, "%02x", (unsigned char)node_data->buff[i]);
	str_buf_append(*outbuf, charb, 2);
	}
	} else {
	for (i = 0; i < 16; i++) {
	if (i > 0 && (i % 4 == 0))
	str_buf_append(*outbuf, " ", 1);
	sprintf(charb, "%02x", (unsigned char)node_data->buff[i]);
	str_buf_append(*outbuf, charb, 2);
	}
	str_buf_append(*outbuf, " ... ", 5);
	for (i = len - 8; i < len; i++) {
	sprintf(charb, "%02x", (unsigned char)node_data->buff[i]);
	str_buf_append(*outbuf, charb, 2);
	if (i > 0 && i < len-1 && (i % 4 == 0))
	str_buf_append(*outbuf, " ", 1);
	}
	}
	str_buf_append(*outbuf, ">", 1);
	}
	break;
	case PLIST_DATE:
	{
	Time64_T timev = (Time64_T)node_data->realval + MAC_EPOCH;
	struct TM _btime;
	struct TM *btime = gmtime64_r(&timev, &_btime);
	if (btime) {
	val = (char*)calloc(1, 26);
	struct tm _tmcopy;
	copy_TM64_to_tm(btime, &_tmcopy);
	val_len = strftime(val, 26, "%Y-%m-%d %H:%M:%S +0000", &_tmcopy);
	if (val_len > 0) {
	str_buf_append(*outbuf, val, val_len);
	}
	free(val);
	val = NULL;
	}
	}
	break;
	case PLIST_UID:
	{
	str_buf_append(*outbuf, "CF$UID:", 7);
	val = (char*)malloc(64);
	if (node_data->length == 16) {
	val_len = snprintf(val, 64, "%"PRIu64, node_data->intval);
	} else {
	val_len = snprintf(val, 64, "%"PRIi64, node_data->intval);
	}
	str_buf_append(*outbuf, val, val_len);
	free(val);
	}
	break;
	default:
	return PLIST_ERR_UNKNOWN;
	}

	return PLIST_ERR_SUCCESS;
	}

	#define PO10i_LIMIT (INT64_MAX/10)

	/* based on https://stackoverflow.com/a/4143288 */
	static int num_digits_i(int64_t i)
	{
	int n;
	int64_t po10;
	n=1;
	if (i < 0) {
	i = (i == INT64_MIN) ? INT64_MAX : -i;
	n++;
	}
	po10=10;
	while (i>=po10) {
	n++;
	if (po10 > PO10i_LIMIT) break;
	po10*=10;
	}
	return n;
	}

	#define PO10u_LIMIT (UINT64_MAX/10)

	/* based on https://stackoverflow.com/a/4143288 */
	static int num_digits_u(uint64_t i)
	{
	int n;
	uint64_t po10;
	n=1;
	po10=10;
	while (i>=po10) {
	n++;
	if (po10 > PO10u_LIMIT) break;
	po10*=10;
	}
	return n;
	}

	static int node_estimate_size(node_t node, uint64_t *size, uint32_t depth, uint32_t indent, int partial_data)
	{
	plist_data_t data;
	if (!node) {
	return PLIST_ERR_INVALID_ARG;
	}
	data = plist_get_data(node);
	if (node->children) {
	node_t ch;
	unsigned int n_children = node_n_children(node);
	for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
	int res = node_estimate_size(ch, size, depth + 1, indent, partial_data);
	if (res < 0) {
	return res;
	}
	}
	switch (data->type) {
	case PLIST_DICT:
	*size += 2; // '{' and '}'
	*size += n_children-1; // number of ':' and ','
	*size += n_children; // number of '\n' and extra space
	size += (uint64_t)n_children (depth+indent+1); // indent for every 2nd child
	*size += indent+1; // additional '\n'
	break;
	case PLIST_ARRAY:
	*size += 2; // '[' and ']'
	*size += n_children-1; // number of ','
	*size += n_children; // number of '\n'
	size += (uint64_t)n_children ((depth+indent+1)<<1); // indent for every child
	*size += indent+1; // additional '\n'
	break;
	default:
	break;
	}
	*size += ((depth+indent) << 1); // indent for {} and []
	} else {
	switch (data->type) {
	case PLIST_STRING:
	case PLIST_KEY:
	*size += data->length;
	*size += 2;
	break;
	case PLIST_INT:
	if (data->length == 16) {
	*size += num_digits_u(data->intval);
	} else {
	*size += num_digits_i((int64_t)data->intval);
	}
	break;
	case PLIST_REAL:
	*size += dtostr(NULL, 0, data->realval);
	break;
	case PLIST_BOOLEAN:
	*size += ((data->boolval) ? 4 : 5);
	break;
	case PLIST_NULL:
	*size += 4;
	break;
	case PLIST_DICT:
	case PLIST_ARRAY:
	*size += 2;
	break;
	case PLIST_DATA:
	*size += 2; // < and >
	if (partial_data) {
	*size += 58;
	} else {
	size += data->length 2;
	*size += data->length / 4; // space between 4 byte groups
	}
	break;
	case PLIST_DATE:
	*size += 25;
	break;
	case PLIST_UID:
	*size += 7; // "CF$UID:"
	*size += num_digits_u(data->intval);
	break;
	default:
	#ifdef DEBUG
	fprintf(stderr, "%s: invalid node type encountered\n", __func__);
	#endif
	return PLIST_ERR_UNKNOWN;
	}
	}
	if (depth == 0) {
	*size += 1; // final newline
	}
	return PLIST_ERR_SUCCESS;
	}

	static plist_err_t _plist_write_to_strbuf(plist_t plist, strbuf_t *outbuf, plist_write_options_t options)
	{
	uint8_t indent = 0;
	if (options & PLIST_OPT_INDENT) {
	indent = (options >> 24) & 0xFF;
	}
	uint8_t i;
	for (i = 0; i < indent; i++) {
	str_buf_append(outbuf, " ", 2);
	}
	int res = node_to_string(plist, &outbuf, 0, indent, options & PLIST_OPT_PARTIAL_DATA);
	if (res < 0) {
	return res;
	}
	if (!(options & PLIST_OPT_NO_NEWLINE)) {
	str_buf_append(outbuf, "\n", 1);
	}
	return res;
	}

	plist_err_t plist_write_to_string_default(plist_t plist, char *output, uint32_t length, plist_write_options_t options)
	{
	uint64_t size = 0;
	int res;

	if (!plist \|\| !output \|\| !length) {
	return PLIST_ERR_INVALID_ARG;
	}

	uint8_t indent = 0;
	if (options & PLIST_OPT_INDENT) {
	indent = (options >> 24) & 0xFF;
	}

	res = node_estimate_size(plist, &size, 0, indent, options & PLIST_OPT_PARTIAL_DATA);
	if (res < 0) {
	return res;
	}

	strbuf_t *outbuf = str_buf_new(size);
	if (!outbuf) {
	#if DEBUG
	fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);
	#endif
	return PLIST_ERR_NO_MEM;
	}

	res = _plist_write_to_strbuf(plist, outbuf, options);
	if (res < 0) {
	str_buf_free(outbuf);
	*output = NULL;
	*length = 0;
	return res;
	}
	str_buf_append(outbuf, "\0", 1);

	*output = outbuf->data;
	*length = outbuf->len - 1;

	outbuf->data = NULL;
	str_buf_free(outbuf);

	return PLIST_ERR_SUCCESS;
	}

	plist_err_t plist_write_to_stream_default(plist_t plist, FILE *stream, plist_write_options_t options)
	{
	if (!plist \|\| !stream) {
	return PLIST_ERR_INVALID_ARG;
	}
	strbuf_t *outbuf = str_buf_new_for_stream(stream);
	if (!outbuf) {
	#if DEBUG
	fprintf(stderr, "%s: Could not allocate output buffer\n", __func__);
	#endif
	return PLIST_ERR_NO_MEM;
	}

	int res = _plist_write_to_strbuf(plist, outbuf, options);
	if (res < 0) {
	str_buf_free(outbuf);
	return res;
	}

	str_buf_free(outbuf);

	return PLIST_ERR_SUCCESS;
	}