Initial version.

src/nxt_parse.c

@@ -0,0 +1,344 @@
+
+/*
+ * Copyright (C) Igor Sysoev
+ * Copyright (C) NGINX, Inc.
+ */
+
+#include <nxt_main.h>
+
+
+/*
+ * nxt_int_parse() returns size_t value >= 0 on success,
+ * -1 on failure, and -2 on overflow.
+ */
+
+nxt_int_t
+nxt_int_parse(const u_char *p, size_t len)
+{
+    u_char      c;
+    nxt_uint_t  val;
+
+    if (nxt_fast_path(len != 0)) {
+
+        val = 0;
+
+        do {
+            c = *p++;
+
+            /* Values below '0' become >= 208. */
+            c = c - '0';
+
+            if (nxt_slow_path(c > 9)) {
+                return -1;
+            }
+
+            val = val * 10 + c;
+
+            if (nxt_slow_path((nxt_int_t) val < 0)) {
+                /* An overflow. */
+                return -2;
+            }
+
+            len--;
+
+        } while (len != 0);
+
+        return val;
+    }
+
+    return -1;
+}
+
+
+/*
+ * nxt_size_t_parse() returns size_t value >= 0 on success,
+ * -1 on failure, and -2 on overflow.
+ */
+
+ssize_t
+nxt_size_t_parse(const u_char *p, size_t len)
+{
+    u_char  c;
+    size_t  val;
+
+    if (nxt_fast_path(len != 0)) {
+
+        val = 0;
+
+        do {
+            c = *p++;
+
+            /* Values below '0' become >= 208. */
+            c = c - '0';
+
+            if (nxt_slow_path(c > 9)) {
+                return -1;
+            }
+
+            val = val * 10 + c;
+
+            if (nxt_slow_path((ssize_t) val < 0)) {
+                /* An overflow. */
+                return -2;
+            }
+
+            len--;
+
+        } while (len != 0);
+
+        return val;
+    }
+
+    return -1;
+}
+
+
+/*
+ * nxt_size_parse() parses size string with optional K or M units and
+ * returns size_t value >= 0 on success, -1 on failure, and -2 on overflow.
+ */
+
+ssize_t
+nxt_size_parse(const u_char *p, size_t len)
+{
+    u_char      c, unit;
+    size_t      val, max;
+    nxt_uint_t  shift;
+
+    if (nxt_fast_path(len != 0)) {
+
+        len--;
+
+        /* Upper case. */
+        unit = p[len] & ~0x20;
+
+        switch (unit) {
+
+        case 'G':
+            max = NXT_SIZE_T_MAX >> 30;
+            shift = 30;
+            break;
+
+        case 'M':
+            max = NXT_SIZE_T_MAX >> 20;
+            shift = 20;
+            break;
+
+        case 'K':
+            max = NXT_SIZE_T_MAX >> 10;
+            shift = 10;
+            break;
+
+        default:
+            max = NXT_SIZE_T_MAX;
+            shift = 0;
+            len++;
+            break;
+        }
+
+        if (nxt_fast_path(len != 0)) {
+
+            val = 0;
+
+            do {
+                c = *p++;
+
+                /* Values below '0' become >= 208. */
+                c = c - '0';
+
+                if (nxt_slow_path(c > 9)) {
+                    return -1;
+                }
+
+                val = val * 10 + c;
+
+                if (nxt_slow_path(val > max)) {
+                    /* An overflow. */
+                    return -2;
+                }
+
+                len--;
+
+            } while (len != 0);
+
+            return val << shift;
+        }
+    }
+
+    return -1;
+}
+
+
+/*
+ * nxt_off_t_parse() returns nxt_off_t value >= 0 on success,
+ * -1 on failure, and -2 on overflow.
+ */
+
+nxt_off_t
+nxt_off_t_parse(const u_char *p, size_t len)
+{
+    u_char      c;
+    nxt_uoff_t  val;
+
+    if (nxt_fast_path(len != 0)) {
+
+        val = 0;
+
+        do {
+            c = *p++;
+
+            /* Values below '0' become >= 208. */
+            c = c - '0';
+
+            if (nxt_slow_path(c > 9)) {
+                return -1;
+            }
+
+            val = val * 10 + c;
+
+            if (nxt_slow_path((nxt_off_t) val < 0)) {
+                /* An overflow. */
+                return -2;
+            }
+
+            len--;
+
+        } while (len != 0);
+
+        return val;
+    }
+
+    return -1;
+}
+
+
+/*
+ * nxt_str_int_parse() returns nxt_int_t value >= 0 on success,
+ * -1 on failure, and -2 on overflow and also updates the 's' argument.
+ */
+
+nxt_int_t
+nxt_str_int_parse(nxt_str_t *s)
+{
+    u_char      c, *p;
+    size_t      len;
+    nxt_uint_t  val;
+
+    len = s->len;
+
+    if (nxt_slow_path(len == 0)) {
+        return -1;
+    }
+
+    p = s->data;
+    val = 0;
+
+    do {
+        c = *p;
+
+        /* Values below '0' become >= 208. */
+        c = c - '0';
+
+        if (c > 9) {
+            break;
+        }
+
+        val = val * 10 + c;
+
+        if (nxt_slow_path((nxt_int_t) val < 0)) {
+            /* An overflow. */
+            return -2;
+        }
+
+        p++;
+        len--;
+
+    } while (len != 0);
+
+    s->len = len;
+    s->data = p;
+
+    return val;
+}
+
+
+/*
+ * nxt_number_parse() returns a double value >= 0 and updates the start
+ * argument on success, or returns -1 on failure or -2 on overflow.
+ */
+
+double
+nxt_number_parse(const u_char **start, const u_char *end)
+{
+    u_char        c;
+    nxt_uint_t    integral, frac, power;
+    const u_char  *p;
+
+    p = *start;
+    integral = 0;
+
+    while (p < end) {
+        c = *p;
+
+        if (c == '.') {
+            goto dot;
+        }
+
+        /* Values below '0' become >= 208. */
+        c = c - '0';
+
+        if (c > 9) {
+            break;
+        }
+
+        integral = integral * 10 + c;
+
+        if (nxt_slow_path((nxt_int_t) integral < 0)) {
+            /* An overflow. */
+            return -2;
+        }
+
+        p++;
+    }
+
+    if (nxt_fast_path(p != *start)) {
+        *start = p;
+        return integral;
+    }
+
+    /* No value. */
+    return -1;
+
+dot:
+
+    if (nxt_slow_path(p == *start)) {
+        /* No leading digit before dot. */
+        return -1;
+    }
+
+    frac = 0;
+    power = 1;
+
+    for (p++; p < end; p++) {
+        c = *p;
+
+        /* Values below '0' become >= 208. */
+        c = c - '0';
+
+        if (c > 9) {
+            break;
+        }
+
+        frac = frac * 10 + c;
+        power *= 10;
+
+        if (nxt_slow_path((nxt_int_t) frac < 0 || (nxt_int_t) power < 0)) {
+            /* An overflow. */
+            return -2;
+        }
+    }
+
+    *start = p;
+
+    return integral + (double) frac / power;
+}