Split MARC reader functions out of marcdisp.c. Prepare for MARC format

[yaz-moved-to-github.git] / src / marc_read_iso2709.c

diff --git a/src/marc_read_iso2709.c b/src/marc_read_iso2709.c
new file mode 100644 (file)
index 0000000..aee41b4
--- /dev/null
+++ b/src/marc_read_iso2709.c
@@ -0,0 +1,200 @@
+/*
+ * Copyright (C) 1995-2006, Index Data ApS
+ * See the file LICENSE for details.
+ *
+ * $Id: marc_read_iso2709.c,v 1.1 2006-12-15 12:37:18 adam Exp $
+ */
+
+/**
+ * \file marc_read_iso2709.c
+ * \brief Implements reading of MARC as ISO2709
+ */
+
+#if HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#ifdef WIN32
+#include <windows.h>
+#endif
+
+#include <stdio.h>
+#include <string.h>
+#include <ctype.h>
+#include <yaz/marcdisp.h>
+#include <yaz/wrbuf.h>
+#include <yaz/yaz-util.h>
+
+int yaz_marc_read_iso2709(yaz_marc_t mt, const char *buf, int bsize)
+{
+    int entry_p;
+    int record_length;
+    int indicator_length;
+    int identifier_length;
+    int end_of_directory;
+    int base_address;
+    int length_data_entry;
+    int length_starting;
+    int length_implementation;
+
+    yaz_marc_reset(mt);
+
+    record_length = atoi_n (buf, 5);
+    if (record_length < 25)
+    {
+        yaz_marc_cprintf(mt, "Record length %d < 24", record_length);
+        return -1;
+    }
+    /* ballout if bsize is known and record_length is less than that */
+    if (bsize != -1 && record_length > bsize)
+    {
+        yaz_marc_cprintf(mt, "Record appears to be larger than buffer %d < %d",
+                         record_length, bsize);
+        return -1;
+    }
+    if (yaz_marc_get_debug(mt))
+        yaz_marc_cprintf(mt, "Record length         %5d", record_length);
+
+    yaz_marc_set_leader(mt, buf,
+                        &indicator_length,
+                        &identifier_length,
+                        &base_address,
+                        &length_data_entry,
+                        &length_starting,
+                        &length_implementation);
+
+    /* First pass. determine length of directory & base of data */
+    for (entry_p = 24; buf[entry_p] != ISO2709_FS; )
+    {
+        /* length of directory entry */
+        int l = 3 + length_data_entry + length_starting;
+        if (entry_p + l >= record_length)
+        {
+            yaz_marc_cprintf(mt, "Directory offset %d: end of record."
+                             " Missing FS char", entry_p);
+            return -1;
+        }
+        if (yaz_marc_get_debug(mt))
+        {
+            yaz_marc_cprintf(mt, "Directory offset %d: Tag %.3s",
+                             entry_p, buf+entry_p);
+        }
+        /* Check for digits in length info */
+        while (--l >= 3)
+            if (!isdigit(*(const unsigned char *) (buf + entry_p+l)))
+                break;
+        if (l >= 3)
+        {
+            /* Not all digits, so stop directory scan */
+            yaz_marc_cprintf(mt, "Directory offset %d: Bad value for data"
+                             " length and/or length starting", entry_p);
+            break;
+        }
+        entry_p += 3 + length_data_entry + length_starting;
+    }
+    end_of_directory = entry_p;
+    if (base_address != entry_p+1)
+    {
+        yaz_marc_cprintf(mt, "Base address not at end of directory,"
+                         " base %d, end %d", base_address, entry_p+1);
+    }
+
+    /* Second pass. parse control - and datafields */
+    for (entry_p = 24; entry_p != end_of_directory; )
+    {
+        int data_length;
+        int data_offset;
+        int end_offset;
+        int i;
+        char tag[4];
+        int identifier_flag = 0;
+        int entry_p0 = entry_p;
+
+        memcpy (tag, buf+entry_p, 3);
+        entry_p += 3;
+        tag[3] = '\0';
+        data_length = atoi_n(buf+entry_p, length_data_entry);
+        entry_p += length_data_entry;
+        data_offset = atoi_n(buf+entry_p, length_starting);
+        entry_p += length_starting;
+        i = data_offset + base_address;
+        end_offset = i+data_length-1;
+
+        if (data_length <= 0 || data_offset < 0)
+            break;
+        
+        if (yaz_marc_get_debug(mt))
+        {
+            yaz_marc_cprintf(mt, "Tag: %s. Directory offset %d: data-length %d,"
+                             " data-offset %d",
+                             tag, entry_p0, data_length, data_offset);
+        }
+        if (end_offset >= record_length)
+        {
+            yaz_marc_cprintf(mt, "Directory offset %d: Data out of bounds %d >= %d",
+                             entry_p0, end_offset, record_length);
+            break;
+        }
+        
+        if (memcmp (tag, "00", 2))
+            identifier_flag = 1;  /* if not 00X assume subfields */
+        else if (indicator_length < 4 && indicator_length > 0)
+        {
+            /* Danmarc 00X have subfields */
+            if (buf[i + indicator_length] == ISO2709_IDFS)
+                identifier_flag = 1;
+            else if (buf[i + indicator_length + 1] == ISO2709_IDFS)
+                identifier_flag = 2;
+        }
+
+        if (identifier_flag)
+        {
+            /* datafield */
+            i += identifier_flag-1;
+            yaz_marc_add_datafield(mt, tag, buf+i, indicator_length);
+            i += indicator_length;
+
+            while (i < end_offset &&
+                    buf[i] != ISO2709_RS && buf[i] != ISO2709_FS)
+            {
+                int code_offset = i+1;
+
+                i ++;
+                while (i < end_offset &&
+                        buf[i] != ISO2709_RS && buf[i] != ISO2709_IDFS &&
+                       buf[i] != ISO2709_FS)
+                    i++;
+                yaz_marc_add_subfield(mt, buf+code_offset, i - code_offset);
+            }
+        }
+        else
+        {
+            /* controlfield */
+            int i0 = i;
+            while (i < end_offset && 
+                buf[i] != ISO2709_RS && buf[i] != ISO2709_FS)
+                i++;
+            yaz_marc_add_controlfield(mt, tag, buf+i0, i-i0);
+        }
+        if (i < end_offset)
+        {
+            yaz_marc_cprintf(mt, "Separator but not at end of field length=%d",
+                    data_length);
+        }
+        if (buf[i] != ISO2709_RS && buf[i] != ISO2709_FS)
+        {
+            yaz_marc_cprintf(mt, "No separator at end of field length=%d",
+                    data_length);
+        }
+    }
+    return record_length;
+}
+
+/*
+ * Local variables:
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ * vim: shiftwidth=4 tabstop=8 expandtab
+ */
+