Commit ac3be565 authored by Nikias Bassen's avatar Nikias Bassen

xplist: Improve memory usage by estimating output buffer size

parent 3007c970
......@@ -26,7 +26,7 @@
typedef struct bytearray_t strbuf_t;
#define str_buf_new() byte_array_new(32768)
#define str_buf_new(__sz) byte_array_new(__sz)
#define str_buf_free(__ba) byte_array_free(__ba)
#define str_buf_grow(__ba, __am) byte_array_grow(__ba, __am)
#define str_buf_append(__ba, __str, __len) byte_array_append(__ba, (void*)(__str), __len)
......
......@@ -37,6 +37,7 @@
#include <inttypes.h>
#include <math.h>
#include <limits.h>
#include <node.h>
#include <node_list.h>
......@@ -69,6 +70,8 @@
#define MAC_EPOCH 978307200
#define MAX_DATA_BYTES_PER_LINE(__i) (((76 - (__i << 3)) >> 2) * 3)
static const char XML_PLIST_PROLOG[] = "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n\
<!DOCTYPE plist PUBLIC \"-//Apple//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n\
<plist version=\"1.0\">\n";
......@@ -290,7 +293,7 @@ static void node_to_xml(node_t* node, bytearray_t **outbuf, uint32_t depth)
char *buf = malloc(80);
uint32_t j = 0;
uint32_t indent = (depth > 8) ? 8 : depth;
uint32_t maxread = ((76 - indent*8) / 4) * 3;
uint32_t maxread = MAX_DATA_BYTES_PER_LINE(indent);
size_t count = 0;
size_t b64count = 0;
size_t amount = (node_data->length / 3 * 4) + 4 + (((node_data->length / maxread) + 1) * (indent+1));
......@@ -400,9 +403,131 @@ static void parse_date(const char *strval, struct TM *btime)
btime->tm_isdst=0;
}
#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;
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 void node_estimate_size(node_t *node, uint64_t *size, uint32_t depth)
{
plist_data_t data;
if (!node) {
return;
}
data = plist_get_data(node);
if (node->children) {
node_t *ch;
for (ch = node_first_child(node); ch; ch = node_next_sibling(ch)) {
node_estimate_size(ch, size, depth + 1);
}
switch (data->type) {
case PLIST_DICT:
*size += (XPLIST_DICT_LEN << 1) + 7;
break;
case PLIST_ARRAY:
*size += (XPLIST_ARRAY_LEN << 1) + 7;
break;
default:
break;
}
*size += (depth << 1);
} else {
uint32_t indent = (depth > 8) ? 8 : depth;
switch (data->type) {
case PLIST_DATA: {
uint32_t req_lines = (data->length / MAX_DATA_BYTES_PER_LINE(indent)) + 1;
uint32_t b64len = data->length + (data->length / 3);
b64len += b64len % 4;
*size += b64len;
*size += (XPLIST_DATA_LEN << 1) + 5 + (indent+1) * (req_lines+1) + 1;
} break;
case PLIST_STRING:
*size += data->length;
*size += (XPLIST_STRING_LEN << 1) + 6;
break;
case PLIST_KEY:
*size += data->length;
*size += (XPLIST_KEY_LEN << 1) + 6;
break;
case PLIST_UINT:
if (data->length == 16) {
*size += num_digits_u(data->intval);
} else {
*size += num_digits_i((int64_t)data->intval);
}
*size += (XPLIST_INT_LEN << 1) + 6;
break;
case PLIST_REAL:
*size += num_digits_i((int64_t)data->realval) + 7;
*size += (XPLIST_REAL_LEN << 1) + 6;
break;
case PLIST_DATE:
*size += 20; /* YYYY-MM-DDThh:mm:ssZ */
*size += (XPLIST_DATE_LEN << 1) + 6;
break;
case PLIST_BOOLEAN:
*size += ((data->boolval) ? XPLIST_TRUE_LEN : XPLIST_FALSE_LEN) + 4;
break;
case PLIST_DICT:
*size += XPLIST_DICT_LEN + 4; /* <dict/> */
break;
case PLIST_ARRAY:
*size += XPLIST_ARRAY_LEN + 4; /* <array/> */
break;
case PLIST_UID:
*size += num_digits_i((int64_t)data->intval);
*size += (XPLIST_DICT_LEN << 1) + 7;
*size += indent + ((indent+1) << 1);
*size += 18; /* <key>CF$UID</key> */
*size += (XPLIST_INT_LEN << 1) + 6;
break;
default:
break;
}
*size += indent;
}
}
PLIST_API void plist_to_xml(plist_t plist, char **plist_xml, uint32_t * length)
{
strbuf_t *outbuf = str_buf_new();
uint64_t size = 0;
node_estimate_size(plist, &size, 0);
size += sizeof(XML_PLIST_PROLOG) + sizeof(XML_PLIST_EPILOG) - 1;
strbuf_t *outbuf = str_buf_new(size);
str_buf_append(outbuf, XML_PLIST_PROLOG, sizeof(XML_PLIST_PROLOG)-1);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment