[ncman] zlib implementation, quick and dirty

src/lib/notcurses.c

@@ -794,16 +794,33 @@ int ncplane_resize_internal(ncplane* n, int keepy, int keepx,
   int keptarea = keepleny * keeplenx;
   int newarea = ylen * xlen;
   size_t fbsize = sizeof(nccell) * newarea;
-  nccell* fb = malloc(fbsize);
-  if(fb == NULL){
+  // an important optimization is the case where nothing needs to be moved,
+  // true when either the keptarea is 0 or the old and new x dimensions are
+  // equal, and we're keeping the full x dimension, and any material we're
+  // keeping starts at the top. in this case, we try to realloc() and avoid
+  // any copying whatsoever (we otherwise incur at least one copy due to
+  // always using a new area). set realloced high in this event, so we don't
+  // free anything.
+  nccell* fb;
+  bool realloced = false;
+  if(keptarea == 0 || (cols == xlen && cols == keeplenx && keepy == 0)){
+    if((fb = realloc(n->fb, fbsize)) == NULL){
       return -1;
     }
+    realloced = true;
+  }else{
+    if((fb = malloc(fbsize)) == NULL){
+      return -1;
+    }
+  }
   if(n->tam){
     loginfo("TAM realloc to %d entries\n", newarea);
     // FIXME first, free any disposed auxiliary vectors!
     tament* tmptam = realloc(n->tam, sizeof(*tmptam) * newarea);
     if(tmptam == NULL){
+      if(!realloced){
         free(fb);
+      }
       return -1;
     }
     n->tam = tmptam;
@@ -831,16 +848,20 @@ int ncplane_resize_internal(ncplane* n, int keepy, int keepx,
   n->absy += keepy + yoff;
   n->absx += keepx + xoff;
 //fprintf(stderr, "absx: %d keepx: %d xoff: %d\n", n->absx, keepx, xoff);
-  if(keptarea == 0){ // keep nothing, resize/move only
+  if(keptarea == 0){ // keep nothing, resize/move only.
     // if we're keeping nothing, dump the old egcspool. otherwise, we go ahead
     // and keep it. perhaps we ought compact it?
     memset(fb, 0, sizeof(*fb) * newarea);
     egcpool_dump(&n->pool);
-    n->lenx = xlen;
-    n->leny = ylen;
-    free(preserved);
-    return resize_callbacks_children(n);
+  }else if(realloced){
+    // the x dimensions are equal, and we're keeping across the width. only the
+    // y dimension changed. at worst, we need zero some out.
+    unsigned tozorch = (ylen - keepleny) * xlen;
+    if(tozorch){
+      unsigned zorchoff = keepleny * xlen;
+      memset(fb + zorchoff, 0, tozorch);
     }
+  }else{
     // we currently have maxy rows of maxx cells each. we will be keeping rows
     // keepy..keepy + keepleny - 1 and columns keepx..keepx + keeplenx - 1.
     // anything else is zerod out. itery is the row we're writing *to*, and we
@@ -872,9 +893,12 @@ int ncplane_resize_internal(ncplane* n, int keepy, int keepx,
         }
       }
     }
+  }
   n->lenx = xlen;
   n->leny = ylen;
+  if(!realloced){
     free(preserved);
+  }
   return resize_callbacks_children(n);
 }
 

src/man/main.c

@@ -54,6 +54,10 @@ parse_args(int argc, char** argv){
 static unsigned char*
 map_gzipped_data(unsigned char* buf, size_t* len, unsigned char* ubuf, uint32_t ulen){
   struct libdeflate_decompressor* inflate = libdeflate_alloc_decompressor();
+  if(inflate == NULL){
+    munmap(buf, *len);
+    return NULL;
+  }
   size_t outbytes;
   enum libdeflate_result r;
   r = libdeflate_gzip_decompress(inflate, buf, *len, ubuf, ulen, &outbytes);
@@ -66,11 +70,30 @@ map_gzipped_data(unsigned char* buf, size_t* len, unsigned char* ubuf, uint32_t
   return ubuf;
 }
 #else // libz implementation
-#error libz not yet implemented, need libdeflate
 static unsigned char*
 map_gzipped_data(unsigned char* buf, size_t* len, unsigned char* ubuf, uint32_t ulen){
+  z_stream z = {
+    .zalloc = Z_NULL,
+    .zfree = Z_NULL,
+    .opaque = Z_NULL,
+    .next_in = buf,
+    .avail_in = len,
+    .next_out = ubuf,
+    .avail_out = ulen,
+  };
+  int r = inflateInit(&z);
+  if(r != Z_OK){
+    munmap(buf, *len);
+    return NULL;
+  }
+  r = inflate(&z, Z_FLUSH);
+  munmap(buf, *len);
+  if(r != Z_STREAM_END){
+    inflateEnd(&z);
+    return NULL;
+  }
+  inflateEnd(&z);
   munmap(buf, *len);
-  (void)ulen; // FIXME
   return NULL;
 }
 #endif