Hash utilities: maintain a hash state object, not a bundle of arguments.

[u/mdw/catacomb] / cc-hash.c

diff --git a/cc-hash.c b/cc-hash.c
index 81a06a2..9e23f79 100644 (file)
--- a/cc-hash.c
+++ b/cc-hash.c
@@ -37,6 +37,7 @@
 #include <string.h>
 
 #include <mLib/dstr.h>
+#include <mLib/str.h>
 
 #include <mLib/hex.h>
 #include <mLib/base32.h>
@@ -165,10 +166,61 @@ const encodeops *getencoding(const char *ename)
 
 /*----- File hashing ------------------------------------------------------*/
 
+/* --- @gethash@ --- *
+ *
+ * Arguments:  @const char *name@ = pointer to name string
+ *
+ * Returns:    Pointer to appropriate hash class.
+ *
+ * Use:                Chooses a hash function by name.
+ */
+
+const gchash *gethash(const char *name)
+{
+  const gchash *const *g, *gg = 0;
+  size_t sz = strlen(name);
+  for (g = ghashtab; *g; g++) {
+    if (strncmp(name, (*g)->name, sz) == 0) {
+      if ((*g)->name[sz] == 0) {
+       gg = *g;
+       break;
+      } else if (gg)
+       return (0);
+      else
+       gg = *g;
+    }
+  }
+  return (gg);
+}
+
+/* --- @fhash_init@ ---*
+ *
+ * Arguments:  @fhashstate *fh@ = pointer to fhash state to initialize
+ *             @const gchash *gch@ = hash class to set
+ *             @unsigned f@ initial flags to set
+ *
+ * Returns:    ---
+ *
+ * Use:                Initializes an @fhashstate@ structure.
+ */
+
+void fhash_init(fhashstate *fh, const gchash *gch, unsigned f)
+  { fh->f = f; fh->gch = gch; }
+
+/* --- @fhash_free@ --- *
+ *
+ * Arguments:  @fhashstate *fh@ = pointer to fhash state to free
+ *
+ * Returns:    ---
+ *
+ * Use:                Frees an fhash state.
+ */
+
+void fhash_free(fhashstate *fh) { return; }
+
 /* --- @fhash@ --- *
  *
- * Arguments:  @const gchash *gch@ = pointer to hash function to use
- *             @unsigned f@ = flags to set
+ * Arguments:  @fhashstate *fh@ = pointer to fhash state
  *             @const char *file@ = file name to be hashed (null for stdin)
  *             @void *buf@ = pointer to hash output buffer
  *
@@ -177,7 +229,7 @@ const encodeops *getencoding(const char *ename)
  * Use:                Hashes a file.
  */
 
-int fhash(const gchash *gch, unsigned f, const char *file, void *buf)
+int fhash(fhashstate *fh, const char *file, void *buf)
 {
   FILE *fp;
   char fbuf[1024 * 128];
@@ -188,26 +240,97 @@ int fhash(const gchash *gch, unsigned f, const char *file, void *buf)
 
   if (!file || strcmp(file, "-") == 0)
     fp = stdin;
-  else if ((fp = fopen(file, f & FHF_BINARY ? "rb" : "r")) == 0)
+  else if ((fp = fopen(file, fh->f & FHF_BINARY ? "rb" : "r")) == 0)
     return (-1);
 
-  if (f & FHF_PROGRESS) {
+  if (fh->f & FHF_PROGRESS) {
     if (fprogress_init(&ff, file, fp)) return (-1);
   }
 
-  h = GH_INIT(gch);
+  h = GH_INIT(fh->gch);
   while ((sz = fread(fbuf, 1, sizeof(fbuf), fp)) > 0) {
     GH_HASH(h, fbuf, sz);
-    if (f & FHF_PROGRESS) fprogress_update(&ff, sz);
+    if (fh->f & FHF_PROGRESS) fprogress_update(&ff, sz);
   }
   if (ferror(fp)) rc = -1;
   if (fp != stdin) fclose(fp);
-  if (f & FHF_PROGRESS) fprogress_done(&ff);
+  if (fh->f & FHF_PROGRESS) fprogress_done(&ff);
   GH_DONE(h, buf);
   GH_DESTROY(h);
   return (rc);
 }
 
+/* --- @hfparse@ --- *
+ *
+ * Arguments:  @hfpctx *hfp@ = pointer to the context structure
+ *
+ * Returns:    A code indicating what happened.
+ *
+ * Use:                Parses a line from the input file.
+ */
+
+int hfparse(hfpctx *hfp)
+{
+  char *p, *q;
+  const gchash *gch;
+  const encodeops *ee;
+  dstr *d = hfp->dline;
+  size_t hsz;
+
+  /* --- Fetch the input line and get ready to parse --- */
+
+  DRESET(d);
+  if (dstr_putline(d, hfp->fp) == EOF) return (HF_EOF);
+  p = d->buf;
+
+  /* --- Parse magic comments --- */
+
+  if (*p == '#') {
+    p++;
+    if ((q = str_getword(&p)) == 0) return (HF_BAD);
+    if (strcmp(q, "hash") == 0) {
+      if ((q = str_getword(&p)) == 0) return (HF_BAD);
+      if ((gch = gethash(q)) == 0) return (HF_BAD);
+      hfp->gch = gch;
+      return (HF_HASH);
+    } else if (strcmp(q, "encoding") == 0) {
+      if ((q = str_getword(&p)) == 0) return (HF_BAD);
+      if ((ee = getencoding(q)) == 0) return (HF_BAD);
+      hfp->ee = ee;
+      return (HF_ENC);
+    } else if (strcmp(q, "escape") == 0) {
+      hfp->f |= HFF_ESCAPE;
+      return (HF_ESC);
+    }
+    return (HF_BAD);
+  }
+
+  /* --- Otherwise it's a file line --- */
+
+  q = p;
+  while (*p && *p != ' ') p++;
+  if (!*p) return (HF_BAD);
+  *p++ = 0;
+  hsz = hfp->gch->hashsz;
+  if (hfp->ee->get(q, hfp->hbuf, hsz, 0) < hsz) return (HF_BAD);
+  switch (*p) {
+    case '*': hfp->f |= FHF_BINARY; break;
+    case ' ': hfp->f &= ~FHF_BINARY; break;
+    default: return (HF_BAD);
+  }
+  p++;
+
+  DRESET(hfp->dfile);
+  if (hfp->f & HFF_ESCAPE)
+    getstring(&p, hfp->dfile, GSF_STRING);
+  else {
+    dstr_putm(hfp->dfile, p, d->len - (p - d->buf));
+    dstr_putz(hfp->dfile);
+  }
+
+  return (HF_FILE);
+}
+
 /*----- String I/O --------------------------------------------------------*/
 
 /* --- @getstring@ --- *