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[ruby/prism] Change pm_integer_t structure

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https://github.com/ruby/prism/commit/588acf823f
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tompng 2024-02-29 01:36:14 +09:00 committed by Kevin Newton
parent 5113d6b059
commit 81f02eb6ba
6 changed files with 214 additions and 210 deletions
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14
prism/extension.c
View File

@ -1047,12 +1047,16 @@ integer_parse(VALUE self, VALUE source) {
pm_integer_t integer = { 0 };
pm_integer_parse(&integer, PM_INTEGER_BASE_UNKNOWN, start, start + length);
VALUE number = UINT2NUM(integer.head.value);
size_t shift = 0;
VALUE number;
for (pm_integer_word_t *node = integer.head.next; node != NULL; node = node->next) {
VALUE receiver = rb_funcall(UINT2NUM(node->value), rb_intern("<<"), 1, ULONG2NUM(++shift * 32));
number = rb_funcall(receiver, rb_intern("|"), 1, number);
if (integer.values == NULL) {
number = UINT2NUM(integer.value);
} else {
number = UINT2NUM(0);
for (size_t i = 0; i < integer.length; i++) {
VALUE receiver = rb_funcall(UINT2NUM(integer.values[i]), rb_intern("<<"), 1, ULONG2NUM(i * 32));
number = rb_funcall(receiver, rb_intern("|"), 1, number);
}
}
if (integer.negative) number = rb_funcall(number, rb_intern("-@"), 0);

15
prism/static_literals.c
View File

@ -53,12 +53,11 @@ node_hash(const pm_parser_t *parser, const pm_node_t *node) {
case PM_INTEGER_NODE: {
// Integers hash their value.
const pm_integer_t *integer = &((const pm_integer_node_t *) node)->value;
const uint32_t *value = &integer->head.value;
uint32_t hash = murmur_hash((const uint8_t *) value, sizeof(uint32_t));
for (const pm_integer_word_t *word = integer->head.next; word != NULL; word = word->next) {
value = &word->value;
hash ^= murmur_hash((const uint8_t *) value, sizeof(uint32_t));
uint32_t hash;
if (integer->values) {
hash = murmur_hash((const uint8_t *) integer->values, sizeof(uint32_t) * integer->length);
} else {
hash = murmur_hash((const uint8_t *) &integer->value, sizeof(uint32_t));
}
if (integer->negative) {
@ -204,9 +203,9 @@ pm_int64_value(const pm_parser_t *parser, const pm_node_t *node) {
switch (PM_NODE_TYPE(node)) {
case PM_INTEGER_NODE: {
const pm_integer_t *integer = &((const pm_integer_node_t *) node)->value;
if (integer->length > 0) return integer->negative ? INT64_MIN : INT64_MAX;
if (integer->values) return integer->negative ? INT64_MIN : INT64_MAX;
int64_t value = (int64_t) integer->head.value;
int64_t value = (int64_t) integer->value;
return integer->negative ? -value : value;
}
case PM_SOURCE_LINE_NODE:

14
prism/templates/ext/prism/api_node.c.erb
View File

@ -40,20 +40,20 @@ pm_string_new(const pm_string_t *string, rb_encoding *encoding) {
static VALUE
pm_integer_new(const pm_integer_t *integer) {
VALUE result;
if (integer->head.next) {
size_t length = integer->length + 1;
VALUE str = rb_str_new(NULL, length * 8);
if (integer->values) {
VALUE str = rb_str_new(NULL, integer->length * 8);
unsigned char *buf = (unsigned char *)RSTRING_PTR(str);
size_t offset = length * 8;
for (const pm_integer_word_t *node = &integer->head; node != NULL; node = node->next) {
size_t offset = integer->length * 8;
for (size_t i = 0; i < integer->length; i++) {
uint32_t value = integer->values[i];
for (int i = 0; i < 8; i++) {
int n = (node->value >> (4 * i)) & 0xf;
int n = (value >> (4 * i)) & 0xf;
buf[--offset] = n < 10 ? n + '0' : n - 10 + 'a';
}
}
result = rb_funcall(str, rb_intern("to_i"), 1, UINT2NUM(16));
} else {
result = UINT2NUM(integer->head.value);
result = UINT2NUM(integer->value);
}
if (integer->negative) {

12
prism/templates/src/serialize.c.erb
View File

@ -52,10 +52,14 @@ pm_serialize_string(const pm_parser_t *parser, const pm_string_t *string, pm_buf
static void
pm_serialize_integer(const pm_integer_t *integer, pm_buffer_t *buffer) {
pm_buffer_append_byte(buffer, integer->negative ? 1 : 0);
pm_buffer_append_varuint(buffer, pm_sizet_to_u32(integer->length + 1));
for (const pm_integer_word_t *node = &integer->head; node != NULL; node = node->next) {
pm_buffer_append_varuint(buffer, node->value);
if (integer->values == NULL) {
pm_buffer_append_varuint(buffer, pm_sizet_to_u32(1));
pm_buffer_append_varuint(buffer, integer->value);
} else {
pm_buffer_append_varuint(buffer, pm_sizet_to_u32(integer->length));
for (size_t i = 0; i < integer->length; i++) {
pm_buffer_append_varuint(buffer, integer->values[i]);
}
}
}

338
prism/util/pm_integer.c
View File

@ -1,20 +1,14 @@
#include "prism/util/pm_integer.h"
/**
* Bigint with arbitary base. In practice, base is 1<<32 or 10**9.
* When base is 10**9, it acts as bigdecimal.
* Adds two positive pm_integer_t with the given base.
* Return pm_integer_t with values allocated. Not normalized.
*/
typedef struct {
size_t length;
uint32_t *values;
} bigint_t;
/**
* Adds two bigint_t with the given base.
*/
static bigint_t
big_add(bigint_t left, bigint_t right, uint64_t base) {
size_t length = (left.length < right.length ? right.length : left.length);
static pm_integer_t
big_add(pm_integer_t left_, pm_integer_t right_, uint64_t base) {
pm_integer_t left = left_.values ? left_ : (pm_integer_t) { 0, 1, &left_.value, false };
pm_integer_t right = right_.values ? right_ : (pm_integer_t) { 0, 1, &right_.value, false };
size_t length = left.length < right.length ? right.length : left.length;
uint32_t *values = (uint32_t*) malloc(sizeof(uint32_t) * (length + 1));
uint64_t carry = 0;
for (size_t i = 0; i < length; i++) {
@ -26,15 +20,19 @@ big_add(bigint_t left, bigint_t right, uint64_t base) {
values[length] = (uint32_t) carry;
length++;
}
return (bigint_t) { length, values };
return (pm_integer_t) { 0, length, values, false };
}
/**
* Calculates `a - b - c` with the given base.
* Result is assumed to be positive value. Internal use for karatsuba_multiply.
* Internal use for karatsuba_multiply. Calculates `a - b - c` with the given
* base. Assume a, b, c, a - b - c all to be poitive.
* Return pm_integer_t with values allocated. Not normalized.
*/
static bigint_t
big_sub2(bigint_t a, bigint_t b, bigint_t c, uint64_t base) {
static pm_integer_t
big_sub2(pm_integer_t a_, pm_integer_t b_, pm_integer_t c_, uint64_t base) {
pm_integer_t a = a_.values ? a_ : (pm_integer_t) { 0, 1, &a_.value, false };
pm_integer_t b = b_.values ? b_ : (pm_integer_t) { 0, 1, &b_.value, false };
pm_integer_t c = c_.values ? c_ : (pm_integer_t) { 0, 1, &c_.value, false };
size_t length = a.length;
uint32_t *values = (uint32_t*) malloc(sizeof(uint32_t) * length);
int64_t carry = 0;
@ -50,16 +48,19 @@ big_sub2(bigint_t a, bigint_t b, bigint_t c, uint64_t base) {
}
}
while (length > 1 && values[length - 1] == 0) length--;
return (bigint_t) { length, values };
return (pm_integer_t) { 0, length, values, false };
}
/**
* Multiply two bigint_t with the given base using karatsuba algorithm.
* Multiply two positive integers with the given base using karatsuba algorithm.
* Return pm_integer_t with values allocated. Not normalized.
*/
static bigint_t
karatsuba_multiply(bigint_t left, bigint_t right, uint64_t base) {
static pm_integer_t
karatsuba_multiply(pm_integer_t left_, pm_integer_t right_, uint64_t base) {
pm_integer_t left = left_.values ? left_ : (pm_integer_t) { 0, 1, &left_.value, false };
pm_integer_t right = right_.values ? right_ : (pm_integer_t) { 0, 1, &right_.value, false };
if (left.length > right.length) {
bigint_t temp = left;
pm_integer_t temp = left;
left = right;
right = temp;
}
@ -76,40 +77,40 @@ karatsuba_multiply(bigint_t left, bigint_t right, uint64_t base) {
values[i + right.length] = carry;
}
while (length > 1 && values[length - 1] == 0) length--;
return (bigint_t) { length, values };
return (pm_integer_t) { 0, length, values, false };
}
if (left.length * 2 <= right.length) {
uint32_t *values = (uint32_t*) calloc(left.length + right.length, sizeof(uint32_t));
for (size_t start_offset = 0; start_offset < right.length; start_offset += left.length) {
size_t end_offset = start_offset + left.length;
if (end_offset > right.length) end_offset = right.length;
bigint_t sliced_right = { end_offset - start_offset, right.values + start_offset };
bigint_t v = karatsuba_multiply(left, sliced_right, base);
pm_integer_t sliced_right = { 0, end_offset - start_offset, right.values + start_offset, false };
pm_integer_t v = karatsuba_multiply(left, sliced_right, base);
uint32_t carry = 0;
for (size_t i = 0; i < v.length; i++) {
uint64_t sum = (uint64_t) values[start_offset + i] + v.values[i] + carry;
values[start_offset + i] = (uint32_t) (sum % base);
carry = (uint32_t) (sum / base);
}
free(v.values);
values[start_offset + v.length] += carry;
if (carry > 0) values[start_offset + v.length] += carry;
pm_integer_free(&v);
}
return (bigint_t) { left.length + right.length, values };
return (pm_integer_t) { 0, left.length + right.length, values, false };
}
size_t half = left.length / 2;
bigint_t x0 = { half, left.values };
bigint_t x1 = { left.length - half, left.values + half };
bigint_t y0 = { half, right.values };
bigint_t y1 = { right.length - half, right.values + half };
bigint_t z0 = karatsuba_multiply(x0, y0, base);
bigint_t z2 = karatsuba_multiply(x1, y1, base);
pm_integer_t x0 = { 0, half, left.values, false };
pm_integer_t x1 = { 0, left.length - half, left.values + half, false };
pm_integer_t y0 = { 0, half, right.values, false };
pm_integer_t y1 = { 0, right.length - half, right.values + half, false };
pm_integer_t z0 = karatsuba_multiply(x0, y0, base);
pm_integer_t z2 = karatsuba_multiply(x1, y1, base);
// For simplicity to avoid considering negative values,
// use `z1 = (x0 + x1) * (y0 + y1) - z0 - z2` instead of original karatsuba algorithm.
bigint_t x01 = big_add(x0, x1, base);
bigint_t y01 = big_add(y0, y1, base);
bigint_t xy = karatsuba_multiply(x01, y01, base);
bigint_t z1 = big_sub2(xy, z0, z2, base);
pm_integer_t x01 = big_add(x0, x1, base);
pm_integer_t y01 = big_add(y0, y1, base);
pm_integer_t xy = karatsuba_multiply(x01, y01, base);
pm_integer_t z1 = big_sub2(xy, z0, z2, base);
size_t length = left.length + right.length;
uint32_t *values = (uint32_t*) calloc(length, sizeof(uint32_t));
@ -127,13 +128,13 @@ karatsuba_multiply(bigint_t left, bigint_t right, uint64_t base) {
carry = (uint32_t) (sum / base);
}
while (length > 1 && values[length - 1] == 0) length--;
free(z0.values);
free(z1.values);
free(z2.values);
free(x01.values);
free(y01.values);
free(xy.values);
return (bigint_t) { length, values };
pm_integer_free(&z0);
pm_integer_free(&z1);
pm_integer_free(&z2);
pm_integer_free(&x01);
pm_integer_free(&y01);
pm_integer_free(&xy);
return (pm_integer_t) { 0, length, values, false };
}
/**
@ -163,67 +164,95 @@ pm_integer_parse_digit(const uint8_t character) {
}
/**
* Create a bigint_t from uint64_t with the given base.
* Create a pm_integer_t from uint64_t with the given base.
*/
static bigint_t
uint64_to_bigint(uint64_t value, uint64_t base) {
static pm_integer_t
pm_integer_from_uint64(uint64_t value, uint64_t base) {
if (value < base) {
return (pm_integer_t) { (uint32_t) value, 0, NULL, false };
}
uint64_t v = value;
size_t len = 0;
while (value > 0) { len++; value /= base; }
if (len == 0) len = 1;
uint32_t *values = (uint32_t*) malloc(sizeof(uint32_t) * len);
for (size_t i = 0; i < len; i++) {
values[i] = (uint32_t) (v % base);
v /= base;
}
return (bigint_t) { len, values };
return (pm_integer_t) { 0, len, values, false };
}
/**
* Convert base of bigint.
* Normalize pm_integer_t.
* Heading zero values will be removed. If the integer fits into uint32_t,
* values is set to NULL, length is set to 0, and value field will be used.
*/
static void
pm_integer_normalize(pm_integer_t *integer) {
if (integer->values == NULL) {
return;
}
while (integer->length > 1 && integer->values[integer->length - 1] == 0) {
integer->length--;
}
if (integer->length > 1) {
return;
}
uint32_t value = integer->values[0];
bool negative = integer->negative && value != 0;
pm_integer_free(integer);
*integer = (pm_integer_t) { value, 0, NULL, negative };
}
/**
* Convert base of the integer.
* In practice, it converts 10**9 to 1<<32 or 1<<32 to 10**9.
*/
static bigint_t
karatsuba_convert_base(bigint_t source, uint64_t base_from, uint64_t base_to) {
static pm_integer_t
pm_integer_convert_base(pm_integer_t source_, uint64_t base_from, uint64_t base_to) {
pm_integer_t source = source_.values ? source_ : (pm_integer_t) { 0, 1, &source_.value, source_.negative };
size_t bigints_length = (source.length + 1) / 2;
bigint_t *bigints = (bigint_t*) malloc(sizeof(bigint_t) * bigints_length);
pm_integer_t *bigints = (pm_integer_t*) malloc(sizeof(pm_integer_t) * bigints_length);
for (size_t i = 0; i < source.length; i += 2) {
uint64_t v = source.values[i] + base_from * (i + 1 < source.length ? source.values[i + 1] : 0);
bigints[i / 2] = uint64_to_bigint(v, base_to);
bigints[i / 2] = pm_integer_from_uint64(v, base_to);
}
bigint_t base = uint64_to_bigint(base_from, base_to);
pm_integer_t base = pm_integer_from_uint64(base_from, base_to);
while (bigints_length > 1) {
size_t new_length = (bigints_length + 1) / 2;
bigint_t new_base = karatsuba_multiply(base, base, base_to);
free(base.values);
pm_integer_t new_base = karatsuba_multiply(base, base, base_to);
pm_integer_free(&base);
base = new_base;
bigint_t *new_bigints = (bigint_t*) malloc(sizeof(bigint_t) * new_length);
pm_integer_t *new_bigints = (pm_integer_t*) malloc(sizeof(pm_integer_t) * new_length);
for (size_t i = 0; i < bigints_length; i += 2) {
if (i + 1 == bigints_length) {
new_bigints[i / 2] = bigints[i];
} else {
bigint_t multiplied = karatsuba_multiply(base, bigints[i + 1], base_to);
pm_integer_t multiplied = karatsuba_multiply(base, bigints[i + 1], base_to);
new_bigints[i / 2] = big_add(bigints[i], multiplied, base_to);
free(bigints[i].values);
free(bigints[i + 1].values);
free(multiplied.values);
pm_integer_free(&bigints[i]);
pm_integer_free(&bigints[i + 1]);
pm_integer_free(&multiplied);
}
}
free(bigints);
bigints = new_bigints;
bigints_length = new_length;
}
free(base.values);
bigint_t result = bigints[0];
pm_integer_free(&base);
pm_integer_t result = bigints[0];
result.negative = source.negative;
free(bigints);
pm_integer_normalize(&result);
return result;
}
/**
* Convert digits to bigint_t with the given power-of-two base.
* Convert digits to integer with the given power-of-two base.
*/
static bigint_t
big_parse_powof2(uint32_t base, const uint8_t *digits, size_t digits_length) {
static void
pm_integer_parse_powof2(pm_integer_t *integer, uint32_t base, const uint8_t *digits, size_t digits_length) {
size_t bit = 1;
while (base > (uint32_t) (1 << bit)) bit++;
size_t length = (digits_length * bit + 31) / 32;
@ -237,32 +266,31 @@ big_parse_powof2(uint32_t base, const uint8_t *digits, size_t digits_length) {
if (32 - shift < bit) values[index + 1] |= value >> (32 - shift);
}
while (length > 1 && values[length - 1] == 0) length--;
return (bigint_t) { length, values };
*integer = (pm_integer_t) { 0, length, values, false };
pm_integer_normalize(integer);
}
/**
* Convert decimal digits to bigint.
* Convert decimal digits to pm_integer_t.
*/
static bigint_t
big_parse_decimal(const uint8_t *digits, size_t digits_length) {
// Construct a bigdecimal from the digits.
static void
pm_integer_parse_decimal(pm_integer_t *integer, const uint8_t *digits, size_t digits_length) {
// Construct a bigdecimal with base = 10**9 from the digits
const size_t batch = 9;
const uint64_t batch_base = 1000000000;
size_t values_length = (digits_length + batch - 1) / batch;
bigint_t bigint = { values_length, (uint32_t*) calloc(values_length, sizeof(uint32_t)) };
pm_integer_t decimal = { 0, values_length, (uint32_t*) calloc(values_length, sizeof(uint32_t)), false };
uint32_t v = 0;
for (size_t i = 0; i < digits_length; i++) {
v = v * 10 + digits[i];
size_t reverse_index = digits_length - i - 1;
if (reverse_index % batch == 0) {
bigint.values[reverse_index / batch] = v;
decimal.values[reverse_index / batch] = v;
v = 0;
}
}
// Convert bigint base from 10**9 to 1<<32.
bigint_t converted = karatsuba_convert_base(bigint, batch_base, ((uint64_t) 1 << 32));
free(bigint.values);
return converted;
// Convert base from 10**9 to 1<<32.
*integer = pm_integer_convert_base(decimal, 1000000000, ((uint64_t) 1 << 32));
pm_integer_free(&decimal);
}
/**
@ -277,22 +305,12 @@ pm_integer_parse_big(pm_integer_t *integer, uint32_t multiplier, const uint8_t *
if (*start == '_') continue;
digits[digits_length++] = (uint8_t) pm_integer_parse_digit(*start);
}
// Construct bigint_t from the digits.
bigint_t bigint =
multiplier == 10 ? big_parse_decimal(digits, digits_length) : big_parse_powof2(multiplier, digits, digits_length);
// Pack bigint_t to pm_integer_t.
integer->length = bigint.length - 1;
integer->head.value = bigint.values[0];
pm_integer_word_t *current = &integer->head;
for (size_t i = 1; i < bigint.length; i++) {
current->next = malloc(sizeof(pm_integer_word_t));
current = current->next;
current->value = bigint.values[i];
current->next = NULL;
// Construct pm_integer_t from the digits.
if (multiplier == 10) {
pm_integer_parse_decimal(integer, digits, digits_length);
} else {
pm_integer_parse_powof2(integer, multiplier, digits, digits_length);
}
free(bigint.values);
free(digits);
}
@ -351,13 +369,13 @@ pm_integer_parse(pm_integer_t *integer, pm_integer_base_t base, const uint8_t *s
if (*ptr == '_') continue;
value = value * multiplier + pm_integer_parse_digit(*ptr);
if (value > UINT32_MAX) {
// If the integer is too large to fit into a single node, then we'll
// If the integer is too large to fit into a single uint32_t, then we'll
// parse it as a big integer.
pm_integer_parse_big(integer, multiplier, start, end);
return;
}
}
integer->head.value = (uint32_t) value;
integer->value = (uint32_t) value;
}
/**
@ -365,7 +383,7 @@ pm_integer_parse(pm_integer_t *integer, pm_integer_base_t base, const uint8_t *s
*/
size_t
pm_integer_memsize(const pm_integer_t *integer) {
return sizeof(pm_integer_t) + integer->length * sizeof(pm_integer_word_t);
return sizeof(pm_integer_t) + integer->length * sizeof(uint32_t);
}
/**
@ -378,16 +396,21 @@ pm_integer_compare(const pm_integer_t *left, const pm_integer_t *right) {
if (left->negative != right->negative) return left->negative ? -1 : 1;
int negative = left->negative ? -1 : 1;
if (left->length < right->length) return -1 * negative;
if (left->length > right->length) return 1 * negative;
if (left->values == right->values) {
if (left->value < right->value) return -1 * negative;
if (left->value > right->value) return 1 * negative;
return 0;
}
for (
const pm_integer_word_t *left_word = &left->head, *right_word = &right->head;
left_word != NULL && right_word != NULL;
left_word = left_word->next, right_word = right_word->next
) {
if (left_word->value < right_word->value) return -1 * negative;
if (left_word->value > right_word->value) return 1 * negative;
if (left->values == NULL || left->length < right->length) return -1 * negative;
if (right->values == NULL || left->length > right->length) return 1 * negative;
for (size_t i = 0; i < left->length; i++) {
size_t index = left->length - i - 1;
uint32_t l = left->values[index];
uint32_t r = right->values[index];
if (l < r) return -1 * negative;
if (l > r) return 1 * negative;
}
return 0;
@ -402,75 +425,54 @@ pm_integer_string(pm_buffer_t *buffer, const pm_integer_t *integer) {
pm_buffer_append_byte(buffer, '-');
}
switch (integer->length) {
case 0: {
const uint32_t value = integer->head.value;
pm_buffer_append_format(buffer, "%" PRIu32, value);
return;
}
case 1: {
const uint64_t value = ((uint64_t) integer->head.value) | (((uint64_t) integer->head.next->value) << 32);
pm_buffer_append_format(buffer, "%" PRIu64, value);
return;
}
default: {
// Pack pm_integer_t to bigint_t.
size_t length = integer->length + 1;
uint32_t *values = calloc(length, sizeof(uint32_t));
const pm_integer_word_t *current = &(integer->head);
for (size_t i = 0; i < length; i++) {
values[i] = current->value;
current = current->next;
}
bigint_t bigint = { length, values };
// Convert bigint base from 1<<32 to 10**9.
bigint_t converted = karatsuba_convert_base(bigint, (uint64_t) 1 << 32, 1000000000);
free(values);
// Allocate a buffer that we'll copy the decimal digits into.
size_t char_length = converted.length * 9;
char *digits = calloc(char_length, sizeof(char));
if (digits == NULL) return;
// Pack bigdecimal to digits.
for (size_t i = 0; i < converted.length; i++) {
uint32_t v = converted.values[i];
for (size_t j = 0; j < 9; j++) {
digits[char_length - 9 * i - j - 1] = (char) ('0' + v % 10);
v /= 10;
}
}
size_t start_offset = 0;
while (start_offset < char_length - 1 && digits[start_offset] == '0') start_offset++;
// Finally, append the string to the buffer and free the digits.
pm_buffer_append_string(buffer, digits + start_offset, char_length - start_offset);
free(digits);
free(converted.values);
return;
}
if (integer->values == NULL) {
pm_buffer_append_format(buffer, "%" PRIu32, integer->value);
return;
}
}
/**
* Recursively destroy the linked list of an integer.
*/
static void
pm_integer_word_destroy(pm_integer_word_t *integer) {
if (integer->next != NULL) {
pm_integer_word_destroy(integer->next);
if (integer->length == 2) {
const uint64_t value = ((uint64_t) integer->values[0]) | ((uint64_t) integer->values[1] << 32);
pm_buffer_append_format(buffer, "%" PRIu64, value);
return;
}
xfree(integer);
// Convert base from 1<<32 to 10**9.
pm_integer_t converted = pm_integer_convert_base(*integer, (uint64_t) 1 << 32, 1000000000);
if (converted.values == NULL) {
pm_buffer_append_format(buffer, "%" PRIu32, converted.value);
pm_integer_free(&converted);
return;
}
// Allocate a buffer that we'll copy the decimal digits into.
size_t char_length = converted.length * 9;
char *digits = calloc(char_length, sizeof(char));
if (digits == NULL) return;
// Pack bigdecimal to digits.
for (size_t i = 0; i < converted.length; i++) {
uint32_t v = converted.values[i];
for (size_t j = 0; j < 9; j++) {
digits[char_length - 9 * i - j - 1] = (char) ('0' + v % 10);
v /= 10;
}
}
size_t start_offset = 0;
while (start_offset < char_length - 1 && digits[start_offset] == '0') start_offset++;
// Finally, append the string to the buffer and free the digits.
pm_buffer_append_string(buffer, digits + start_offset, char_length - start_offset);
free(digits);
pm_integer_free(&converted);
}
/**
* Free the internal memory of an integer. This memory will only be allocated if
* the integer exceeds the size of a single node in the linked list.
* the integer exceeds the size of a single uint32_t.
*/
PRISM_EXPORTED_FUNCTION void
pm_integer_free(pm_integer_t *integer) {
if (integer->head.next) {
pm_integer_word_destroy(integer->head.next);
if (integer->values) {
free(integer->values);
}
}

31
prism/util/pm_integer.h
View File

@ -15,30 +15,25 @@
#include <stdlib.h>
/**
* A node in the linked list of a pm_integer_t.
*/
typedef struct pm_integer_word {
/** A pointer to the next node in the list. */
struct pm_integer_word *next;
/** The value of the node. */
uint32_t value;
} pm_integer_word_t;
/**
* This structure represents an arbitrary-sized integer. It is implemented as a
* linked list of 32-bit integers, with the least significant digit at the head
* of the list.
* A structure represents an arbitrary-sized integer.
*/
typedef struct {
/** The number of nodes in the linked list that have been allocated. */
/**
* Embedded value for small integer. This value is set to 0 if the value
* does not fit into uint32_t.
*/
uint32_t value;
/**
* The number of allocated values. length is set to 0 if the integer fits
* into uint32_t.
*/
size_t length;
/**
* The head of the linked list, embedded directly so that allocations do not
* need to be performed for small integers.
* List of 32-bit integers. Set to NULL if the integer fits into uint32_t.
*/
pm_integer_word_t head;
uint32_t *values;
/**
* Whether or not the integer is negative. It is stored this way so that a