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#include "jsi.h"
/* Dynamically grown string buffer */
void js_putc(js_State *J, js_Buffer **sbp, int c)
{
js_Buffer *sb = *sbp;
if (!sb) {
sb = js_malloc(J, sizeof *sb);
sb->n = 0;
sb->m = sizeof sb->s;
*sbp = sb;
} else if (sb->n == sb->m) {
sb = js_realloc(J, sb, (sb->m *= 2) + soffsetof(js_Buffer, s));
*sbp = sb;
}
sb->s[sb->n++] = c;
}
void js_puts(js_State *J, js_Buffer **sb, const char *s)
{
while (*s)
js_putc(J, sb, *s++);
}
void js_putm(js_State *J, js_Buffer **sb, const char *s, const char *e)
{
while (s < e)
js_putc(J, sb, *s++);
}
/* Use an AA-tree to quickly look up interned strings. */
struct js_StringNode
{
js_StringNode *left, *right;
int level;
char string[1];
};
static js_StringNode jsS_sentinel = { &jsS_sentinel, &jsS_sentinel, 0, ""};
static js_StringNode *jsS_newstringnode(js_State *J, const char *string, const char **result)
{
int n = strlen(string);
js_StringNode *node = js_malloc(J, soffsetof(js_StringNode, string) + n + 1);
node->left = node->right = &jsS_sentinel;
node->level = 1;
memcpy(node->string, string, n + 1);
return *result = node->string, node;
}
static js_StringNode *jsS_skew(js_StringNode *node)
{
if (node->left->level == node->level) {
js_StringNode *temp = node;
node = node->left;
temp->left = node->right;
node->right = temp;
}
return node;
}
static js_StringNode *jsS_split(js_StringNode *node)
{
if (node->right->right->level == node->level) {
js_StringNode *temp = node;
node = node->right;
temp->right = node->left;
node->left = temp;
++node->level;
}
return node;
}
static js_StringNode *jsS_insert(js_State *J, js_StringNode *node, const char *string, const char **result)
{
if (node != &jsS_sentinel) {
int c = strcmp(string, node->string);
if (c < 0)
node->left = jsS_insert(J, node->left, string, result);
else if (c > 0)
node->right = jsS_insert(J, node->right, string, result);
else
return *result = node->string, node;
node = jsS_skew(node);
node = jsS_split(node);
return node;
}
return jsS_newstringnode(J, string, result);
}
static void dumpstringnode(js_StringNode *node, int level)
{
int i;
if (node->left != &jsS_sentinel)
dumpstringnode(node->left, level + 1);
printf("%d: ", node->level);
for (i = 0; i < level; ++i)
putchar('\t');
printf("'%s'\n", node->string);
if (node->right != &jsS_sentinel)
dumpstringnode(node->right, level + 1);
}
void jsS_dumpstrings(js_State *J)
{
js_StringNode *root = J->strings;
printf("interned strings {\n");
if (root && root != &jsS_sentinel)
dumpstringnode(root, 1);
printf("}\n");
}
static void jsS_freestringnode(js_State *J, js_StringNode *node)
{
if (node->left != &jsS_sentinel) jsS_freestringnode(J, node->left);
if (node->right != &jsS_sentinel) jsS_freestringnode(J, node->right);
js_free(J, node);
}
void jsS_freestrings(js_State *J)
{
if (J->strings && J->strings != &jsS_sentinel)
jsS_freestringnode(J, J->strings);
}
const char *js_intern(js_State *J, const char *s)
{
const char *result;
if (!J->strings)
J->strings = &jsS_sentinel;
J->strings = jsS_insert(J, J->strings, s, &result);
return result;
}
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