From f89d0c407e0a581826559dc1e118cb6583889849 Mon Sep 17 00:00:00 2001
From: Holden Rohrer <hr@hrhr.dev>
Date: Mon, 30 Mar 2020 17:21:54 -0400
Subject: cleanup and a bugfix

peekstrbuf didn't properly move its str pointer when creating, so it
only worked on the granularity of the object. There is a pattern here
that still needs to be cleaned up significantly (iterators using min()
internally to determine their end, sort of).
---
 buf.c | 36 +++++++++++++++++++++---------------
 1 file changed, 21 insertions(+), 15 deletions(-)

diff --git a/buf.c b/buf.c
index df35d0f..65bc7a7 100644
--- a/buf.c
+++ b/buf.c
@@ -52,28 +52,34 @@ void shortenbuf(buf* buffer){
     buf_node* tmp = buffer->tail;
     buffer->tail = buffer->tail->next;
     free(tmp);
-    buffer->pop = 0;
 }
 
 char popchrbuf(buf* buffer){
-    if (buffer->pop == buffer->cap) shortenbuf(buffer);
+    if (buffer->pop == buffer->cap){
+        shortenbuf(buffer);
+        buffer->pop = 0;
+    }
     buffer->pop++;
     return buffer->tail->text[buffer->pop-1];
 }
 char* popstrbuf(buf* buffer, size_t ct){
     char* str = malloc((ct+1)*sizeof(char)); str[ct] = 0;
-    size_t rem;
-    for (size_t loc = 0; ct>loc; loc += rem){
-        if (buffer->pop == buffer->cap) shortenbuf(buffer);
-        rem = min(buffer->cap, ct-loc);
-        memcpy(str+loc, buffer->tail->text+buffer->pop, rem);
-        buffer->pop += rem;
-    } /* probably some inefficiencies here*/
+    memcpy(str, buffer->tail->text+buffer->pop,
+        min(ct, buffer->cap-buffer->pop));
+    size_t loc;
+    for (loc = buffer->cap - buffer->pop; loc < ct; loc += buffer->cap){
+        shortenbuf(buffer);
+        memcpy(str+loc, buffer->tail->text, min(ct-loc, buffer->cap));
+    }
+    buffer->pop = ct - loc + buffer->cap;
     return str;
 }
 
 void inschrbuf(buf* buffer, char chr){
-    if (buffer->ins == buffer->cap) extendbuf(buffer);
+    if (buffer->ins == buffer->cap){
+        extendbuf(buffer);
+        buffer->ins = 0;
+    }
     buffer->ins++;
     buffer->head->text[buffer->ins-1] = chr;
 }
@@ -81,12 +87,11 @@ void insstrbuf(buf* buffer, char* str){
     size_t len = strlen(str);
     size_t tgt = min(len, buffer->cap - buffer->ins);
     memcpy(buffer->head->text+buffer->ins, str, tgt);
-    buffer->ins += len;
-    buffer->ins %= buffer->cap;
     for (;tgt<len; tgt += buffer->cap){
         extendbuf(buffer);
         memcpy(buffer->head->text, str+tgt, min(len-tgt, buffer->cap));
     }
+    buffer->ins = len - tgt + buffer->cap;
 }
 
 char* peekstrbuf(buf* buffer, size_t loc, size_t len){
@@ -96,9 +101,10 @@ char* peekstrbuf(buf* buffer, size_t loc, size_t len){
     loc += buffer->pop;
     for (start = buffer->tail; loc>buffer->cap; loc -= buffer->cap)
         start = start->next; // start,loc is where one starts streaming
-    while (len > 0){
-        memcpy(str, start->text+loc, min(buffer->cap-loc, len));
-        len -= min(buffer->cap - loc, len);
+    size_t bytect;
+    for (size_t tgt = 0; len > 0; len -= bytect, tgt += bytect){
+        bytect = min(buffer->cap - loc, len);
+        memcpy(str+tgt, start->text+loc, bytect);
         loc = 0;
     }
     return str;
-- 
cgit