String buffers, part 2d: basic string buffer methods.

Sponsored by fmad.io.

1 files changed, 277 insertions, 1 deletions

diff --git a/src/lib_buffer.c b/src/lib_buffer.c
index c9ef9510e..78c4eeb94 100644
--- a/src/lib_buffer.c
+++ b/src/lib_buffer.c
@@ -14,14 +14,286 @@
 
 #if LJ_HASBUFFER
 #include "lj_gc.h"
+#include "lj_err.h"
 #include "lj_buf.h"
+#include "lj_str.h"
+#include "lj_tab.h"
+#include "lj_udata.h"
+#include "lj_meta.h"
+#if LJ_HASFFI
+#include "lj_ctype.h"
+#include "lj_cdata.h"
+#include "lj_cconv.h"
+#endif
+#include "lj_strfmt.h"
 #include "lj_serialize.h"
 #include "lj_lib.h"
 
 /* ------------------------------------------------------------------------ */
 
+#define LJLIB_MODULE_buffer_method
+
+/* Check that the first argument is a string buffer. */
+static SBufExt *buffer_tobuf(lua_State *L)
+{
+  if (!(L->base < L->top && tvisbuf(L->base)))
+    lj_err_argtype(L, 1, "buffer");
+  return bufV(L->base);
+}
+
+/* Ditto, but for writers. */
+static LJ_AINLINE SBufExt *buffer_tobufw(lua_State *L)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  setsbufXL_(sbx, L);
+  return sbx;
+}
+
+LJLIB_CF(buffer_method_free)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  lj_bufx_free(G(L), sbx);
+  lj_bufx_init(L, sbx);
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_reset)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  lj_bufx_reset(sbx);
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_skip)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  MSize n = (MSize)lj_lib_checkintrange(L, 2, 0, LJ_MAX_BUF);
+  MSize len = sbufxlen(sbx);
+  if (n < len) {
+    sbx->r += n;
+  } else {
+    sbx->r = sbx->w = sbx->b;
+  }
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_set)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  const char *p;
+  MSize len;
+#if LJ_HASFFI
+  if (tviscdata(L->base+1)) {
+    CTState *cts = ctype_cts(L);
+    lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p,
+                   L->base+1, CCF_ARG(2));
+    len = (MSize)lj_lib_checkintrange(L, 3, 0, LJ_MAX_BUF);
+  } else
+#endif
+  {
+    GCstr *str = lj_lib_checkstrx(L, 2);
+    p = strdata(str);
+    len = str->len;
+  }
+  lj_bufx_free(G(L), sbx);
+  lj_bufx_init_cow(L, sbx, p, len);
+  setgcref(sbx->cowref, gcV(L->base+1));
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_put)
+{
+  SBufExt *sbx = buffer_tobufw(L);
+  ptrdiff_t arg, narg = L->top - L->base;
+  for (arg = 1; arg < narg; arg++) {
+    cTValue *o = &L->base[arg], *mo = NULL;
+  retry:
+    if (tvisstr(o)) {
+      lj_buf_putstr((SBuf *)sbx, strV(o));
+    } else if (tvisint(o)) {
+      lj_strfmt_putint((SBuf *)sbx, intV(o));
+    } else if (tvisnum(o)) {
+      lj_strfmt_putfnum((SBuf *)sbx, STRFMT_G14, numV(o));
+    } else if (tvisbuf(o)) {
+      SBufExt *sbx2 = bufV(o);
+      lj_buf_putmem((SBuf *)sbx, sbx2->r, sbufxlen(sbx2));
+    } else if (!mo && !tvisnil(mo = lj_meta_lookup(L, o, MM_tostring))) {
+      /* Call __tostring metamethod inline. */
+      copyTV(L, L->top++, mo);
+      copyTV(L, L->top++, o);
+      lua_call(L, 1, 1);
+      o = &L->base[arg];  /* The stack may have been reallocated. */
+      copyTV(L, &L->base[arg], L->top-1);
+      L->top = L->base + narg;
+      goto retry;  /* Retry with the result. */
+    } else {
+      lj_err_argtype(L, arg+1, "string/number/__tostring");
+    }
+    /* Probably not useful to inline other __tostring MMs, e.g. FFI numbers. */
+  }
+  L->top = L->base+1;  /* Chain buffer object. */
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(buffer_method_putf)
+{
+  SBufExt *sbx = buffer_tobufw(L);
+  lj_strfmt_putarg(L, (SBuf *)sbx, 2, 2);
+  L->top = L->base+1;  /* Chain buffer object. */
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(buffer_method_get)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  ptrdiff_t arg, narg = L->top - L->base;
+  if (narg == 1) {
+    narg++;
+    setnilV(L->top++);  /* get() is the same as get(nil). */
+  }
+  for (arg = 1; arg < narg; arg++) {
+    TValue *o = &L->base[arg];
+    MSize n = tvisnil(o) ? LJ_MAX_BUF :
+              (MSize) lj_lib_checkintrange(L, arg+1, 0, LJ_MAX_BUF);
+    MSize len = sbufxlen(sbx);
+    if (n > len) n = len;
+    setstrV(L, o, lj_str_new(L, sbx->r, n));
+    sbx->r += n;
+  }
+  if (sbx->r == sbx->w) sbx->r = sbx->w = sbx->b;
+  lj_gc_check(L);
+  return narg-1;
+}
+
+#if LJ_HASFFI
+LJLIB_CF(buffer_method_putcdata)
+{
+  SBufExt *sbx = buffer_tobufw(L);
+  const char *p;
+  MSize len;
+  if (tviscdata(L->base+1)) {
+    CTState *cts = ctype_cts(L);
+    lj_cconv_ct_tv(cts, ctype_get(cts, CTID_P_CVOID), (uint8_t *)&p,
+                   L->base+1, CCF_ARG(2));
+  } else {
+    lj_err_argtype(L, 2, "cdata");
+  }
+  len = (MSize)lj_lib_checkintrange(L, 3, 0, LJ_MAX_BUF);
+  lj_buf_putmem((SBuf *)sbx, p, len);
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_reserve)
+{
+  SBufExt *sbx = buffer_tobufw(L);
+  MSize len = (MSize)lj_lib_checkintrange(L, 2, 0, LJ_MAX_BUF);
+  GCcdata *cd;
+  lj_buf_more((SBuf *)sbx, len);
+  ctype_loadffi(L);
+  cd = lj_cdata_new_(L, CTID_P_UINT8, CTSIZE_PTR);
+  *(void **)cdataptr(cd) = sbx->w;
+  setcdataV(L, L->top++, cd);
+  setintV(L->top++, sbufleft(sbx));
+  return 2;
+}
+
+LJLIB_CF(buffer_method_commit)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  MSize len = (MSize)lj_lib_checkintrange(L, 2, 0, LJ_MAX_BUF);
+  if (len > sbufleft(sbx)) lj_err_arg(L, 2, LJ_ERR_NUMRNG);
+  sbx->w += len;
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_ref)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  GCcdata *cd;
+  ctype_loadffi(L);
+  cd = lj_cdata_new_(L, CTID_P_UINT8, CTSIZE_PTR);
+  *(void **)cdataptr(cd) = sbx->r;
+  setcdataV(L, L->top++, cd);
+  setintV(L->top++, sbufxlen(sbx));
+  return 2;
+}
+#endif
+
+LJLIB_CF(buffer_method_encode)
+{
+  SBufExt *sbx = buffer_tobufw(L);
+  cTValue *o = lj_lib_checkany(L, 2);
+  lj_serialize_put(sbx, o);
+  lj_gc_check(L);
+  L->top = L->base+1;  /* Chain buffer object. */
+  return 1;
+}
+
+LJLIB_CF(buffer_method_decode)
+{
+  SBufExt *sbx = buffer_tobufw(L);
+  setnilV(L->top++);
+  lj_serialize_get(sbx, L->top-1);
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(buffer_method___gc)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  lj_bufx_free(G(L), sbx);
+  lj_bufx_init(L, sbx);
+  return 0;
+}
+
+LJLIB_CF(buffer_method___tostring)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  setstrV(L, L->top-1, lj_str_new(L, sbx->r, sbufxlen(sbx)));
+  lj_gc_check(L);
+  return 1;
+}
+
+LJLIB_CF(buffer_method___len)
+{
+  SBufExt *sbx = buffer_tobuf(L);
+  setintV(L->top-1, (int32_t)sbufxlen(sbx));
+  return 1;
+}
+
+LJLIB_PUSH("buffer") LJLIB_SET(__metatable)
+LJLIB_PUSH(top-1) LJLIB_SET(__index)
+
+/* ------------------------------------------------------------------------ */
+
 #define LJLIB_MODULE_buffer
 
+LJLIB_PUSH(top-2) LJLIB_SET(!)  /* Set environment. */
+
+LJLIB_CF(buffer_new)
+{
+  MSize sz = L->base == L->top ? 0u :
+             (MSize)lj_lib_checkintrange(L, 1, 0, LJ_MAX_BUF);
+  GCtab *env = tabref(curr_func(L)->c.env);
+  GCudata *ud = lj_udata_new(L, sizeof(SBufExt), env);
+  SBufExt *sbx = (SBufExt *)uddata(ud);
+  ud->udtype = UDTYPE_BUFFER;
+  /* NOBARRIER: The GCudata is new (marked white). */
+  setgcref(ud->metatable, obj2gco(env));
+  setudataV(L, L->top++, ud);
+  lj_bufx_init(L, sbx);
+  if (sz > 0) lj_buf_need2((SBuf *)sbx, sz);
+  return 1;
+}
+
 LJLIB_CF(buffer_encode)
 {
   cTValue *o = lj_lib_checkany(L, 1);
@@ -35,13 +307,14 @@ LJLIB_CF(buffer_encode)
 
 LJLIB_CF(buffer_decode)
 {
-  GCstr *str = lj_lib_checkstr(L, 1);
+  GCstr *str = lj_lib_checkstrx(L, 1);
   SBufExt sbx;
   lj_bufx_init_cow(L, &sbx, strdata(str), str->len);
   /* No need to set sbx.cowref here. */
   setnilV(L->top++);
   lj_serialize_get(&sbx, L->top-1);
   lj_gc_check(L);
+  if (sbx.r != sbx.w) lj_err_caller(L, LJ_ERR_BUFFER_LEFTOV);
   return 1;
 }
 
@@ -51,6 +324,9 @@ LJLIB_CF(buffer_decode)
 
 int luaopen_string_buffer(lua_State *L)
 {
+  LJ_LIB_REG(L, NULL, buffer_method);
+  lua_getfield(L, -1, "__tostring");
+  lua_setfield(L, -2, "tostring");
   LJ_LIB_REG(L, NULL, buffer);
   return 1;
 }