1 files changed, 88 insertions, 0 deletions
diff --git a/sb.c b/sb.c
new file mode 100644
index 0000000..06ee8d9
--- /dev/null
+++ b/sb.c
@@ -0,0 +1,88 @@
+#include <stdlib.h>
+#include <string.h>
+
+#include "sb.h"
+
+struct sb {
+    sbnode* head;
+    sbnode* tail;
+    size_t loc;
+    size_t sz;
+};
+
+struct sbnode {
+    char* str;
+    sbnode* next;
+};
+
+sbnode* newsbnode(sbnode* prev, size_t sz){
+    sbnode* node = malloc(sizeof(sbnode)); // Allocate
+    node->str = malloc(sizeof(char)*(sz+1)); node->str[sz] = 0;
+    node->next = NULL; // Init
+    if (prev) prev->next = node; // Link
+    return node;
+}
+
+sb* newsb(size_t sz){
+    sb* out = malloc(sizeof(sb));
+    out->head = out->tail = newsbnode(NULL, sz);
+    out->sz = sz;
+    out->loc = 0;
+    return out;
+}
+
+void extendsb(sb* buf){
+    buf->sz *= 2;
+    buf->loc = 0;
+    buf->tail = newsbnode(buf->tail, buf->sz);
+}
+
+void insstr(sb* buf, char* str){
+    size_t rem = strlen(str); // remaining chars to push
+    while (rem > (buf->sz - buf->loc)){ // while buffer has less room
+        // than needed, fill the buffer with str
+        memcpy(buf->tail->str+buf->loc, str, buf->sz - buf->loc);
+        // move the string pointer by that amount
+        str += buf->sz - buf->loc;
+        // reduce the number of remaining characters by that amount
+        rem -= buf->sz - buf->loc;
+        // and add a new node, resetting buf->loc
+        extendsb(buf);
+    }
+    // copy the rest into the buffer
+    memcpy(buf->tail->str+buf->loc, str, rem);
+    // and advance buf->loc
+    buf->loc += rem;
+}
+
+sbnode* freenodenext(sbnode* node){
+    sbnode* out = node->next;
+    free(node->str);
+    free(node);
+    return out;
+}
+
+char* decompose(sb* buf){
+    // Make the last node a proper string
+    buf->tail->str[buf->loc] = 0;
+    // Start with the length of the last node
+    size_t len = 0;
+    // For every non-tail node (cur->next == NULL for it),
+    for (sbnode* cur = buf->head; cur != NULL; cur = cur->next){
+        // add the length of its string
+        len += strlen(cur->str);
+    }
+    // make a string to fit it all
+    char* str = malloc(sizeof(char)*(len+1)); str[len] = 0;
+    // and its iterator
+    char* pos = str;
+    // for every node,
+    for (sbnode* cur = buf->head; cur != NULL; cur = freenodenext(cur)){
+        size_t slen = strlen(cur->str);
+        memcpy(pos, cur->str, slen); // copy
+        pos += slen;
+    }
+    free(buf);
+    return str;
+}
+