start in on input thread

src/lib/in.c

@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include "internal.h"
+
+// data collected from responses to our terminal queries.
+typedef struct termqueries {
+  int celly, cellx;     // cell geometry on startup
+  int pixy, pixx;       // pixel geometry on startup
+  int cursory, cursorx; // cursor location on startup
+  unsigned kittygraphs; // are kitty graphics supported?
+  int sixely, sixelx;   // maximum sixel size
+  int cregs;            // sixel color registers
+  unsigned appsync;     // application-sync supported?
+} termqueries;
+
+typedef struct cursorloc {
+  int y, x;             // 0-indexed cursor location
+} cursorloc;
+
+// local state for the input thread
+typedef struct inputctx {
+  // we do not close any of these file descriptors; we don't own them!
+  int termfd;           // terminal fd: -1 with no controlling terminal, or
+                        //  if stdin is a terminal, and on Windows Terminal.
+  int stdinfd;          // stdin fd. always 0.
+#ifdef __MINGW64__
+  HANDLE stdinhandle;   // handle to input terminal
+#endif
+  unsigned char ibuf[BUFSIZ]; // we dump raw reads into this ringbuffer, and
+                              //  process them all post-read
+  cursorloc* csrs;    // cursor reports are dumped here
+  ncinput* inputs;    // processed input is dumped here
+  int csize, isize;   // total number of slots in csrs/inputs
+  int cvalid, ivalid; // population count of csrs/inputs
+  int cwrite, iwrite; // slot where we'll write the next csr/input;
+                      //  we cannot write if valid == size
+  int cread, iread;   // slot from which to read the next csr/input;
+                      //  we cannot read if valid == 0
+  tinfo* ti;          // link back to tinfo
+} inputctx;
+
+static inline inputctx*
+create_inputctx(tinfo* ti){
+  inputctx* i = malloc(sizeof(*i));
+  if(i){
+    i->csize = 64;
+    if( (i->csrs = malloc(sizeof(*i->csrs) * i->csize)) ){
+      i->isize = BUFSIZ;
+      if( (i->inputs = malloc(sizeof(*i->inputs) * i->isize)) ){
+        // FIXME set up infd/handle
+        i->ti = ti;
+        i->cvalid = i->ivalid = 0;
+        i->cwrite = i->iwrite = 0;
+        i->cread = i->iread = 0;
+        return i;
+      }
+      free(i->csrs);
+    }
+    free(i);
+  }
+  return NULL;
+}
+
+static inline void
+free_inputctx(inputctx* i){
+  if(i){
+    // we *do not* own any file descriptors or handles; don't close them!
+    free(i->inputs);
+    free(i->csrs);
+    free(i);
+  }
+}