From ac3be565c413f6964f0188e1c608c1bf8848db29 Mon Sep 17 00:00:00 2001 From: Nikias Bassen Date: Fri, 14 Dec 2018 04:23:05 +0100 Subject: xplist: Improve memory usage by estimating output buffer size --- src/strbuf.h | 2 +- src/xplist.c | 129 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 128 insertions(+), 3 deletions(-) (limited to 'src') diff --git a/src/strbuf.h b/src/strbuf.h index b805892..0d28edf 100644 --- a/src/strbuf.h +++ b/src/strbuf.h @@ -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) diff --git a/src/xplist.c b/src/xplist.c index bb27f53..2eeccf9 100644 --- a/src/xplist.c +++ b/src/xplist.c @@ -37,6 +37,7 @@ #include #include +#include #include #include @@ -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[] = "\n\ \n\ \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; /* */ + break; + case PLIST_ARRAY: + *size += XPLIST_ARRAY_LEN + 4; /* */ + 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; /* CF$UID */ + *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); -- cgit v1.1-32-gdbae