#include <mruby.h>

#include <mruby/array.h>

#include <mruby/class.h>

#include <mruby/string.h>

#include <mruby/range.h>

#include <mruby/proc.h>

#include <mruby/internal.h>

#include "value_array.h"

#define ARY_DEFAULT_LEN 4

#define ARY_SHRINK_RATIO 5 /* must be larger than 2 */

#define ARY_C_MAX_SIZE (SIZE_MAX / sizeof(mrb_value))

#ifndef MRB_ARY_LENGTH_MAX

#define MRB_ARY_LENGTH_MAX 131072

#define ARY_MAX_SIZE ((mrb_int)((ARY_C_MAX_SIZE < (size_t)MRB_INT_MAX) ? ARY_C_MAX_SIZE : MRB_INT_MAX-1))

static void

ary_too_big(mrb_state *mrb)

{

mrb_raise(mrb, E_ARGUMENT_ERROR, "array size too big");

}

static inline void

ary_check_too_big(mrb_state *mrb, mrb_int a, mrb_int b)

{

if (a > ARY_MAX_SIZE - b || a < 0)

ary_too_big(mrb);

#if MRB_ARY_LENGTH_MAX != 0

if (a > MRB_ARY_LENGTH_MAX - b || a < 0)

ary_too_big(mrb);

}

static struct RArray*

ary_new_capa(mrb_state *mrb, mrb_int capa)

{

ary_check_too_big(mrb, capa, 0);

size_t blen = capa * sizeof(mrb_value);

struct RArray *a = MRB_OBJ_ALLOC(mrb, MRB_TT_ARRAY, mrb->array_class);

if (capa <= MRB_ARY_EMBED_LEN_MAX) {

ARY_SET_EMBED_LEN(a, 0);

}

else {

a->as.heap.ptr = (mrb_value *)mrb_malloc(mrb, blen);

a->as.heap.aux.capa = capa;

a->as.heap.len = 0;

}

return a;

}

MRB_API mrb_value

mrb_ary_new_capa(mrb_state *mrb, mrb_int capa)

{

struct RArray *a = ary_new_capa(mrb, capa);

return mrb_obj_value(a);

}

MRB_API mrb_value

mrb_ary_new(mrb_state *mrb)

{

return mrb_ary_new_capa(mrb, 0);

}

static inline void

array_copy(mrb_value *dst, const mrb_value *src, mrb_int size)

{

for (mrb_int i = 0; i < size; i++) {

dst[i] = src[i];

}

}

static struct RArray*

ary_new_from_values(mrb_state *mrb, mrb_int size, const mrb_value *vals)

{

struct RArray *a = ary_new_capa(mrb, size);

array_copy(ARY_PTR(a), vals, size);

ARY_SET_LEN(a, size);

return a;

}

MRB_API mrb_value

mrb_ary_new_from_values(mrb_state *mrb, mrb_int size, const mrb_value *vals)

{

struct RArray *a = ary_new_from_values(mrb, size, vals);

return mrb_obj_value(a);

}

MRB_API mrb_value

mrb_assoc_new(mrb_state *mrb, mrb_value car, mrb_value cdr)

{

struct RArray *a = ary_new_capa(mrb, 2);

mrb_value *p = ARY_PTR(a);

p[0] = car;

p[1] = cdr;

ARY_SET_LEN(a, 2);

return mrb_obj_value(a);

}

static void

ary_fill_with_nil(mrb_value *ptr, mrb_int size)

{

mrb_value nil = mrb_nil_value();

while (size--) {

*ptr++ = nil;

}

}

#define ary_modify_check(mrb, a) mrb_check_frozen((mrb), (a))

static void

ary_modify(mrb_state *mrb, struct RArray *a)

{

ary_modify_check(mrb, a);

if (ARY_SHARED_P(a)) {

mrb_shared_array *shared = a->as.heap.aux.shared;

if (shared->refcnt == 1 && a->as.heap.ptr == shared->ptr) {

a->as.heap.ptr = shared->ptr;

a->as.heap.aux.capa = a->as.heap.len;

mrb_free(mrb, shared);

}

else {

mrb_value *p = a->as.heap.ptr;

mrb_value *ptr = (mrb_value*)mrb_malloc(mrb, a->as.heap.len * sizeof(mrb_value));

if (p) {

array_copy(ptr, p, a->as.heap.len);

}

a->as.heap.ptr = ptr;

a->as.heap.aux.capa = a->as.heap.len;

mrb_ary_decref(mrb, shared);

}

ARY_UNSET_SHARED_FLAG(a);

}

}

MRB_API void

mrb_ary_modify(mrb_state *mrb, struct RArray* a)

{

mrb_write_barrier(mrb, (struct RBasic*)a);

ary_modify(mrb, a);

}

static void

ary_make_shared(mrb_state *mrb, struct RArray *a)

{

if (!ARY_SHARED_P(a) && !ARY_EMBED_P(a)) {

mrb_shared_array *shared = (mrb_shared_array*)mrb_malloc(mrb, sizeof(mrb_shared_array));

mrb_value *ptr = a->as.heap.ptr;

mrb_int len = a->as.heap.len;

shared->refcnt = 1;

if (a->as.heap.aux.capa > len) {

a->as.heap.ptr = shared->ptr = (mrb_value*)mrb_realloc(mrb, ptr, sizeof(mrb_value)*len+1);

}

else {

shared->ptr = ptr;

}

shared->len = len;

a->as.heap.aux.shared = shared;

ARY_SET_SHARED_FLAG(a);

}

}

MRB_API mrb_value

mrb_ary_make_shared_copy(mrb_state *mrb, mrb_value ary)

{

struct RArray *orig = mrb_ary_ptr(ary);

// Frozen arrays don't need protection

if (mrb_frozen_p(orig)) {

return ary;

}

// Embedded arrays can't be shared - make full copy

if (ARY_EMBED_P(orig)) {

return mrb_ary_dup(mrb, ary);

}

// Make original array shared if not already

if (!ARY_SHARED_P(orig)) {

ary_make_shared(mrb, orig);

}

// Create new array that shares the buffer

struct RArray *shared = (struct RArray*)mrb_obj_alloc(mrb, MRB_TT_ARRAY, mrb->array_class);

shared->as.heap.ptr = orig->as.heap.ptr;

shared->as.heap.len = orig->as.heap.len;

shared->as.heap.aux.shared = orig->as.heap.aux.shared;

shared->as.heap.aux.shared->refcnt++;

ARY_SET_SHARED_FLAG(shared);

mrb_write_barrier(mrb, (struct RBasic*)shared);

return mrb_obj_value(shared);

}

static void

ary_expand_capa(mrb_state *mrb, struct RArray *a, mrb_int len)

{

mrb_int capa = ARY_CAPA(a);

ary_check_too_big(mrb, len, 0);

if (capa < ARY_DEFAULT_LEN) {

capa = ARY_DEFAULT_LEN;

}

while (capa < len) {

if (capa <= ARY_MAX_SIZE / 2) {

capa *= 2;

}

else {

capa = len;

}

}

if (capa > ARY_MAX_SIZE) {

ary_too_big(mrb);

}

if (ARY_EMBED_P(a)) {

mrb_value *ptr = ARY_EMBED_PTR(a);

mrb_int slen = ARY_EMBED_LEN(a);

mrb_value *expanded_ptr = (mrb_value*)mrb_malloc(mrb, sizeof(mrb_value)*capa);

ARY_UNSET_EMBED_FLAG(a);

array_copy(expanded_ptr, ptr, slen);

a->as.heap.len = slen;

a->as.heap.aux.capa = capa;

a->as.heap.ptr = expanded_ptr;

}

else if (capa > a->as.heap.aux.capa) {

mrb_value *expanded_ptr = (mrb_value*)mrb_realloc(mrb, a->as.heap.ptr, sizeof(mrb_value)*capa);

a->as.heap.aux.capa = capa;

a->as.heap.ptr = expanded_ptr;

}

}

static void

ary_shrink_capa(mrb_state *mrb, struct RArray *a)

{

if (ARY_EMBED_P(a)) return;

mrb_int capa = a->as.heap.aux.capa;

if (capa < ARY_DEFAULT_LEN * 2) return;

if (capa <= a->as.heap.len * ARY_SHRINK_RATIO) return;

do {

capa /= 2;

if (capa < ARY_DEFAULT_LEN) {

capa = ARY_DEFAULT_LEN;

break;

}

} while (capa > a->as.heap.len * ARY_SHRINK_RATIO);

if (capa > a->as.heap.len && capa < a->as.heap.aux.capa) {

a->as.heap.aux.capa = capa;

a->as.heap.ptr = (mrb_value*)mrb_realloc(mrb, a->as.heap.ptr, sizeof(mrb_value)*capa);

}

}

MRB_API mrb_value

mrb_ary_resize(mrb_state *mrb, mrb_value ary, mrb_int new_len)

{

struct RArray *a = mrb_ary_ptr(ary);

ary_modify(mrb, a);

mrb_int old_len = RARRAY_LEN(ary);

if (old_len != new_len) {

if (new_len < old_len) {

ary_shrink_capa(mrb, a);

}

else {

ary_expand_capa(mrb, a, new_len);

ary_fill_with_nil(ARY_PTR(a) + old_len, new_len - old_len);

}

ARY_SET_LEN(a, new_len);

}

return ary;

}

static mrb_value

mrb_ary_s_create(mrb_state *mrb, mrb_value klass)

{

const mrb_value *vals;

mrb_int len;

mrb_get_args(mrb, "*!", &vals, &len);

mrb_value ary = mrb_ary_new_from_values(mrb, len, vals);

struct RArray *a = mrb_ary_ptr(ary);

a->c = mrb_class_ptr(klass);

return ary;

}

static void ary_replace(mrb_state*, struct RArray*, struct RArray*);

static mrb_value

mrb_ary_init(mrb_state *mrb, mrb_value ary)

{

mrb_value ss = mrb_fixnum_value(0);

mrb_value obj = mrb_nil_value();

mrb_value blk = mrb_nil_value();

mrb_get_args(mrb, "|oo&", &ss, &obj, &blk);

if (mrb_array_p(ss) && mrb_nil_p(obj) && mrb_nil_p(blk)) {

ary_replace(mrb, mrb_ary_ptr(ary), mrb_ary_ptr(ss));

return ary;

}

mrb_int size = mrb_as_int(mrb, ss);

struct RArray *a = mrb_ary_ptr(ary);

/* Rebuilding an array through `initialize` writes over whatever it held,

ary_modify_check(mrb, a);

if (ARY_CAPA(a) < size) {

ary_expand_capa(mrb, a, size);

}

int ai = mrb_gc_arena_save(mrb);

for (mrb_int i=0; i<size; i++) {

mrb_value val;

if (mrb_nil_p(blk)) {

val = obj;

}

else {

val = mrb_yield(mrb, blk, mrb_fixnum_value(i));

}

mrb_ary_set(mrb, ary, i, val);

mrb_gc_arena_restore(mrb, ai); // for mrb_funcall

}

return ary;

}

static void

ary_concat(mrb_state *mrb, struct RArray *a, struct RArray *a2)

{

mrb_int len = ARY_LEN(a);

if (len == 0) {

ary_replace(mrb, a, a2);

return;

}

mrb_int len2 = ARY_LEN(a2);

ary_check_too_big(mrb, len2, len);

ary_modify(mrb, a);

mrb_int newlen = len + len2;

if (ARY_CAPA(a) < newlen) {

ary_expand_capa(mrb, a, newlen);

}

array_copy(ARY_PTR(a)+len, ARY_PTR(a2), len2);

mrb_write_barrier(mrb, (struct RBasic*)a);

ARY_SET_LEN(a, newlen);

}

MRB_API void

mrb_ary_concat(mrb_state *mrb, mrb_value self, mrb_value other)

{

struct RArray *a2 = mrb_ary_ptr(other);

ary_concat(mrb, mrb_ary_ptr(self), a2);

}

static mrb_value

mrb_ary_concat_m(mrb_state *mrb, mrb_value self)

{

mrb_value *args;

mrb_int len;

mrb_get_args(mrb, "*!", &args, &len);

for (int i=0; i<len; i++) {

mrb_ensure_array_type(mrb, args[i]);

}

for (int i=0; i<len; i++) {

mrb_ary_concat(mrb, self, args[i]);

}

return self;

}

static mrb_value

mrb_ary_plus(mrb_state *mrb, mrb_value self)

{

struct RArray *a1 = mrb_ary_ptr(self);

const mrb_value *ptr;

mrb_int blen;

mrb_get_args(mrb, "a", &ptr, &blen);

ary_check_too_big(mrb, ARY_LEN(a1), blen);

mrb_int len1 = ARY_LEN(a1);

struct RArray *a2 = ary_new_capa(mrb, len1 + blen);

array_copy(ARY_PTR(a2), ARY_PTR(a1), len1);

array_copy(ARY_PTR(a2) + len1, ptr, blen);

ARY_SET_LEN(a2, len1+blen);

return mrb_obj_value(a2);

}

#define ARY_REPLACE_SHARED_MIN 20

static void

ary_replace(mrb_state *mrb, struct RArray *a, struct RArray *b)

{

mrb_int len = ARY_LEN(b);

ary_modify_check(mrb, a);

if (a == b) return;

if (ARY_SHARED_P(a)) {

mrb_ary_decref(mrb, a->as.heap.aux.shared);

a->as.heap.aux.capa = 0;

a->as.heap.len = 0;

a->as.heap.ptr = NULL;

ARY_UNSET_SHARED_FLAG(a);

}

if (ARY_SHARED_P(b)) {

shared_b:

if (ARY_EMBED_P(a)) {

ARY_UNSET_EMBED_FLAG(a);

}

else {

mrb_free(mrb, a->as.heap.ptr);

}

a->as.heap.ptr = b->as.heap.ptr;

a->as.heap.len = len;

a->as.heap.aux.shared = b->as.heap.aux.shared;

a->as.heap.aux.shared->refcnt++;

ARY_SET_SHARED_FLAG(a);

mrb_write_barrier(mrb, (struct RBasic*)a);

return;

}

if (len > ARY_REPLACE_SHARED_MIN) {

ary_make_shared(mrb, b);

goto shared_b;

}

if (ARY_CAPA(a) < len)

ary_expand_capa(mrb, a, len);

array_copy(ARY_PTR(a), ARY_PTR(b), len);

mrb_write_barrier(mrb, (struct RBasic*)a);

ARY_SET_LEN(a, len);

}

MRB_API void

mrb_ary_replace(mrb_state *mrb, mrb_value self, mrb_value other)

{

struct RArray *a1 = mrb_ary_ptr(self);

struct RArray *a2 = mrb_ary_ptr(other);

if (a1 != a2) {

ary_replace(mrb, a1, a2);

}

else {

/* Replacing an array with itself leaves it as it was, so ary_replace()

ary_modify_check(mrb, a1);

}

}

static mrb_value

mrb_ary_replace_m(mrb_state *mrb, mrb_value self)

{

mrb_value other;

mrb_get_args(mrb, "A", &other);

mrb_ary_replace(mrb, self, other);

return self;

}

static mrb_value

mrb_ary_times(mrb_state *mrb, mrb_value self)

{

struct RArray *a1 = mrb_ary_ptr(self);

mrb_value arg = mrb_get_arg1(mrb);

mrb_value tmp = mrb_check_string_type(mrb, arg);

if (!mrb_nil_p(tmp)) {

return mrb_ary_join(mrb, self, tmp);

}

mrb_int times = mrb_as_int(mrb, arg);

if (times < 0) {

mrb_raise(mrb, E_ARGUMENT_ERROR, "negative argument");

}

if (times == 0) return mrb_ary_new(mrb);

if (ARY_MAX_SIZE / times < ARY_LEN(a1)) {

ary_too_big(mrb);

}

mrb_int len1 = ARY_LEN(a1);

struct RArray *a2 = ary_new_capa(mrb, len1 * times);

ARY_SET_LEN(a2, len1 * times);

mrb_value *ptr = ARY_PTR(a2);

while (times--) {

array_copy(ptr, ARY_PTR(a1), len1);

ptr += len1;

}

return mrb_obj_value(a2);

}

static mrb_value

mrb_ary_reverse_bang(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

if (len > 1) {

ary_modify(mrb, a);

mrb_value *p1 = ARY_PTR(a);

mrb_value *p2 = p1 + len - 1;

while (p1 < p2) {

mrb_value tmp = *p1;

*p1++ = *p2;

*p2-- = tmp;

}

}

else {

/* One element or none reverses into itself, so the ary_modify() above,

ary_modify_check(mrb, a);

}

return self;

}

static mrb_value

mrb_ary_reverse(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self), *b = ary_new_capa(mrb, ARY_LEN(a));

mrb_int len = ARY_LEN(a);

if (len > 0) {

mrb_value *p1 = ARY_PTR(a);

mrb_value *e = p1 + len;

mrb_value *p2 = ARY_PTR(b) + len - 1;

while (p1 < e) {

*p2-- = *p1++;

}

ARY_SET_LEN(b, len);

}

return mrb_obj_value(b);

}

MRB_API void

mrb_ary_push(mrb_state *mrb, mrb_value ary, mrb_value elem)

{

struct RArray *a = mrb_ary_ptr(ary);

mrb_int len = ARY_LEN(a);

ary_modify(mrb, a);

if (len == ARY_CAPA(a))

ary_expand_capa(mrb, a, len + 1);

ARY_PTR(a)[len] = elem;

ARY_SET_LEN(a, len+1);

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, elem);

}

static mrb_value

mrb_ary_push_m(mrb_state *mrb, mrb_value self)

{

mrb_int argc = mrb_get_argc(mrb);

if (argc == 1) {

mrb_ary_push(mrb, self, mrb_get_argv(mrb)[0]);

return self;

}

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

mrb_int len2 = len + argc;

ary_modify(mrb, a);

if (ARY_CAPA(a) < len2) {

ary_expand_capa(mrb, a, len2);

}

const mrb_value *argv = mrb_get_argv(mrb);

array_copy(ARY_PTR(a)+len, argv, argc);

ARY_SET_LEN(a, len2);

while (argc--) {

mrb_field_write_barrier_value(mrb, (struct RBasic*)a, *argv);

argv++;

}

return self;

}

MRB_API mrb_value

mrb_ary_pop(mrb_state *mrb, mrb_value ary)

{

struct RArray *a = mrb_ary_ptr(ary);

mrb_int len = ARY_LEN(a);

ary_modify_check(mrb, a);

if (len == 0) return mrb_nil_value();

ARY_SET_LEN(a, len-1);

return ARY_PTR(a)[len-1];

}

#define ARY_SHIFT_SHARED_MIN 10

MRB_API mrb_value

mrb_ary_shift(mrb_state *mrb, mrb_value self)

{

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

ary_modify_check(mrb, a);

if (len == 0) return mrb_nil_value();

if (ARY_SHARED_P(a)) {

L_SHIFT:

a->as.heap.ptr++;

a->as.heap.len--;

return a->as.heap.ptr[-1];

}

else if (len > ARY_SHIFT_SHARED_MIN) {

ary_make_shared(mrb, a);

goto L_SHIFT;

}

else {

mrb_value *ptr = ARY_PTR(a);

mrb_int size = len;

mrb_value val = *ptr;

while (--size) {

*ptr = *(ptr+1);

ptr++;

}

ARY_SET_LEN(a, len-1);

return val;

}

}

static mrb_value

mrb_ary_shift_m(mrb_state *mrb, mrb_value self)

{

if (mrb_get_argc(mrb) == 0) {

return mrb_ary_shift(mrb, self);

}

mrb_int n = mrb_as_int(mrb, mrb_get_arg1(mrb));

struct RArray *a = mrb_ary_ptr(self);

mrb_int len = ARY_LEN(a);

ary_modify_check(mrb, a);

if (len == 0 || n == 0) return mrb_ary_new(mrb);

if (n < 0) mrb_raise(mrb, E_ARGUMENT_ERROR, "negative array shift");

if (n > len) n = len;

mrb_value val = mrb_ary_new_from_values(mrb, n, ARY_PTR(a));

if (ARY_SHARED_P(a)) {

L_SHIFT:

a->as.heap.ptr+=n;

a->as.heap.len-=n;

return val;

}

if (len > ARY_SHIFT_SHARED_MIN) {

ary_make_shared(mrb, a);

goto L_SHIFT;

}

else if (len == n) {

ARY_SET_LEN(a, 0);

}

else {

mrb_value *ptr = ARY_PTR(a);

mrb_int size = len-n;

while (size--) {

*ptr = *(ptr+n);

ptr++;

}

ARY_SET_LEN(a, len-n);

}

return val;

}

MRB_API mrb_value